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Objective: Microalbuminuria can reflect the progress of microvascular complications and may be predictive of macrovascular disease in type 2 diabetes. The effect of intensive glycemic control on microalbuminuria in patients in the U.S. who have had type 2 diabetes for several years has not previously been evaluated.Research Design and Methods: We randomly assigned 153 male patients to either intensive treatment (INT) (goal HbA(1c) 7.1%) or to standard treatment (ST) (goal HbA(1c) 9.1%; P = 0.001), and data were obtained during a 2-year period. Mean duration of known diabetes was 8 years, mean age of the patients was 60 years, and patients were well matched at baseline. We obtained 3-h urine samples for each patient at baseline and annually and defined microalbuminuria as an albumin:creatinine ratio of 0.03-0.30. All patients were treated with insulin and received instructions regarding diet and exercise. Hypertension and dyslipidemia were treated with similar goals in each group.Results: A total of 38% of patients had microalbuminuria at entry and were evenly assigned to both treatment groups. INT retarded the progression of microalbuminuria during the 2-year period: the changes in albumin:creatinine ratio from baseline to 2 years of INT versus ST were 0.045 vs. 0.141, respectively (P = 0.046). Retardation of progressive urinary albumin excretion was most pronounced in those patients who entered the study with microalbuminuria and were randomized to INT. Patients entering with microalbuminuria had a deterioration in creatinine clearance at 2 years regardless of the intensity of glycemic control. In the group entering without microalbuminuria, the subgroup receiving ST had a lower percentage of patients with a macrovascular event (17%) than the subgroup receiving INT (36%) (P = 0.03). Use of ACE inhibitors or calcium-channel blockers was similarly distributed among the groups.Conclusions: Intensive glycemic control retards microalbuminuria in patients who have had type 2 diabetes for several years but may not lessen the progressive deterioration of glomerular function. Increases in macrovascular event rates in the subgroup entering without albuminuria who received INT remain unexplained but could reflect early worsening, as observed with microvascular disease in the Diabetes Control and Complications Trial. [ABSTRACT FROM AUTHOR]

Objective: To evaluate performance of process and outcome measures in the care of patients with diabetes seen in Department of Veterans Affairs (VA) facilities.Research Design and Methods: Retrospective audits of records and databases were conducted on randomly selected patients with diabetes over 5 years (1995 [baseline] and 1997-2000) in 22 VA networks. Performance on diabetes-specific and preventive processes was measured.Results: Nationally, significant improvements over time were observed for all measures (P < 0.001). For example, the percentage of patients receiving a dilated retinal examination rose from 44% in 1995 to 67% in 2000. The percentage of patients who received a urinary protein test rose from 23% in 1997 to 54% in 2000. Those who received influenza vaccination rose from 34% in 1995 to 78% in 2000. However, there was significant regional variation among all measures.Conclusions: Adherence to diabetes-specific and preventive care measures in the VA improved from 1997 to 2000 compared with a 1995 baseline. The improvement occurred in a setting of the provision of guidelines, the contractual setting of specific targets, and the timely feedback of results to medical center and network directors. Future studies are needed to determine whether adherence to these measures will decrease the rates of complications in VA patients with diabetes. [ABSTRACT FROM AUTHOR]

Objective: To describe the Veterans Affairs (VA)/Department of Defense (DoD) Clinical Practice Guidelines for diabetes and contrast selected recommendations with those of the American Diabetes Association (ADA).Research Design and Methods: We summarize the general structure of the VA/DoD Guidelines and describe the rationale for recommendations issued in 2003 for glycemic control, management of hypertension, and retinopathy screening. We compare the synthesis of evidence and resulting recommendations for these content areas with the 2004 American Diabetes Association Clinical Practice Recommendations.Results: The VA/DoD Guidelines and the ADA Clinical Practice Recommendations reported similar strength of evidence findings by content area, but clinical recommendations varied. The VA/DoD Guidelines and practice recommendations emphasize the use of data on absolute risk reduction from available published randomized clinical trials rather than relative risk reduction from observational analyses. The VA/DoD Guidelines employ an algorithm-based methodology to guide clinicians through a risk-stratified approach to managing individual patients rather than promoting a single standard for most or all patients without explicit consideration of competing comorbidities.Conclusions: The VA/DoD Guidelines are intended to guide diabetes care by providing Internet-ready, evidence-based annotations in algorithmic form to help clinicians set and revise individual treatment goals for their patients. [ABSTRACT FROM AUTHOR]

Objective: To determine pharmacy costs for glycemic treatment and its relationship to glycemic control in the Department of Veterans Affairs (VA) between 1994 and 2000.Research Design and Methods: Patients with diabetes in the VA in FY1994, FY1996, FY1998, and FY2000 were identified using an ambulatory care pharmacy-derived database. Total drug acquisition costs, as well as expenditures for insulin, oral glycemic control agents, and self-blood glucose monitoring strips, were determined for these veterans. HbA(1c) levels for the corresponding time periods were also obtained. Pharmacy costs (medications and monitoring) were examined by glycemic control treatment type.Results: In FY2000, 18% (n = 535,016) of all VA pharmacy patients were identified as having diabetes, and they received 30% of all pharmacy prescriptions. Overall, 23% of pharmacy expenditures for these patients were related to glycemic control medications and monitoring supplies. Annual pharmacy costs increased from FY1994 to FY2000. The greatest change was the higher expenditure for monitoring supplies through FY1998, which then decreased in FY2000. Increased pharmacy costs were associated with improved glycemic control. In FY2000, the mean last HbA(1c) level (n = 446,384) fell to 7.6% from 7.8% in FY1998 (n = 204,136) and 8.4% in 1996 (n = 53,348).Conclusions: Diabetes was associated with high pharmacy costs. Increasing medication expenditures were associated with improved HbA(1c) levels at the aggregated national level. Policies concerning dispensing monitoring supplies and several diabetes quality improvement projects were initiated during this interval. Future challenges include initiatives to further optimize care while controlling costs. [ABSTRACT FROM AUTHOR]

Background: When the antithyroid drugs were discovered in the early 1940s, they were immediately recognized as a revolutionary new treatment for hyperthyroidism. Although much has been learned about their mechanism of action and clinical utility, they continue to be used today in much the same way as they have been since their introduction. Summary: In 1995, Dr. Clark Sawin gave an address on the history of antithyroid drug development at the 11th International Thyroid Congress in Toronto, Ontario, Canada. In his review, Dr. Sawin recounted the original observations by Drs. Julia and Cosmo Mackenzie and Curt Richter at the Johns Hopkins University School of Medicine, and how their work ultimately led to Dr. Edwin (Ted) B. Astwood's seminal 1943 report on the use of thiourea and thiouracil in the Journal of the American Medical Association. He also described the development of propylthiouracil and methimazole as less toxic alternatives. He concluded his remarks by noting the often-serendipitous pathway of drug development and the role of pharmaceutical companies in the process. Conclusions: Antithyroid drugs remain a cornerstone of thyroid therapeutics. It is informative to review the process by which they came into use, as this is a seminal part of the history of thyroid disease in the 20th century. This knowledge may also spark additional research leading to new pharmacotherapies for patients with hyperthyroidism.

Background: Low serum estradiol has been more strongly associated with low bone mineral density in elderly men than has testosterone, but its association with incident hip fracture is unknown. We examined whether low estradiol increases the risk for future hip fracture among men and explored whether testosterone levels influence this risk., Methods: We examined 793 men (mean age = 71 years) evaluated between 1981 and 1983, who had estradiol measures and no history of hip fracture, and followed until the end of 1999. Total estradiol and testosterone were measured between 1981 and 1983. Hip fractures were identified and confirmed through medical records review through the end of 1999. We created 3 groups of men based on estradiol levels and performed a Cox-proportional hazards model to examine the risk for incident hip fracture, adjusted for age, body mass index, height, and smoking status. We performed similar analyses based on testosterone levels, and then based on both estradiol and testosterone levels together., Results: There were 39 men who sustained an atraumatic hip fracture over follow-up. Incidence rates for hip fracture (per 1000 person-years) were 11.0, 3.4, and 3.9 for the low (2.0-18.1 pg/mL [7-67 pmol/L]), middle (18.2-34.2 pg/mL [67-125 pmol/L]), and high (> or =34.3 pg/mL [> or =126 pmol/L]) estradiol groups, respectively. With adjustment for age, body mass index, height, and smoking status, the adjusted hazard ratios for men in the low and middle estradiol groups, relative to the high group, were 3.1 (95% confidence interval [CI], 1.4-6.9) and 0.9 (95% CI, 0.4-2.0), respectively. In similar adjusted analyses evaluating men by their testosterone levels, we found no significant increased risk for hip fracture. However, in analyses in which we grouped men by both estradiol and testosterone levels, we found that men with both low estradiol and low testosterone levels had the greatest risk for hip fracture (adjusted hazard ratio: 6.5, 95% CI, 2.9-14.3)., Conclusion: Men with low estradiol levels are at an increased risk for future hip fracture. Men with both low estradiol and low testosterone levels seem to be at greatest risk for hip fracture.

Context: Patients with serum thyroid-stimulating hormone (TSH) levels outside the reference range and levels of free thyroxine (FT4) and triiodothyronine (T3) within the reference range are common in clinical practice. The necessity for further evaluation, possible treatment, and the urgency of treatment have not been clearly established., Objectives: To define subclinical thyroid disease, review its epidemiology, recommend an appropriate evaluation, explore the risks and benefits of treatment and consequences of nontreatment, and determine whether population-based screening is warranted., Data Sources: MEDLINE, EMBASE, Biosis, the Agency for Healthcare Research and Quality, National Guideline Clearing House, the Cochrane Database of Systematic Reviews and Controlled Trials Register, and several National Health Services (UK) databases were searched for articles on subclinical thyroid disease published between 1995 and 2002. Articles published before 1995 were recommended by expert consultants., Study Selection and Data Extraction: A total of 195 English-language or translated papers were reviewed. Editorials, individual case studies, studies enrolling fewer than 10 patients, and nonsystematic reviews were excluded. Information related to authorship, year of publication, number of subjects, study design, and results were extracted and formed the basis for an evidence report, consisting of tables and summaries of each subject area., Data Synthesis: The strength of the evidence that untreated subclinical thyroid disease is associated with clinical symptoms and adverse clinical outcomes was assessed and recommendations for clinical practice developed. Data relating the progression of subclinical to overt hypothyroidism were rated as good, but data relating treatment to prevention of progression were inadequate to determine a treatment benefit. Data relating a serum TSH level higher than 10 mIU/L to elevations in serum cholesterol were rated as fair but data relating to benefits of treatment were rated as insufficient. All other associations of symptoms and benefit of treatment were rated as insufficient or absent. Data relating a serum TSH concentration lower than 0.1 mIU/L to the presence of atrial fibrillation and progression to overt hyperthyroidism were rated as good, but no data supported treatment to prevent these outcomes. Data relating restoration of the TSH level to within the reference range with improvements in bone mineral density were rated as fair. Data addressing all other associations of subclinical hyperthyroid disease and adverse clinical outcomes or treatment benefits were rated as insufficient or absent. Subclinical hypothyroid disease in pregnancy is a special case and aggressive case finding and treatment in pregnant women can be justified., Conclusions: Data supporting associations of subclinical thyroid disease with symptoms or adverse clinical outcomes or benefits of treatment are few. The consequences of subclinical thyroid disease (serum TSH 0.1-0.45 mIU/L or 4.5-10.0 mIU/L) are minimal and we recommend against routine treatment of patients with TSH levels in these ranges. There is insufficient evidence to support population-based screening. Aggressive case finding is appropriate in pregnant women, women older than 60 years, and others at high risk for thyroid dysfunction.

Subclinical hyperthyroidism is characterized by a clearly low serum concentration of thyrotropin (TSH) and the absence of obvious symptoms of hyperthyroidism. Whether or not all persons with a low value for serum TSH can be considered subclinically hyperthyroid is uncertain, but the low serum TSH per se is a risk factor for atrial fibrillation and perhaps other cardiovascular disease. Screening all persons, even in the older age groups, for subclinical hyperthyroidism may not be justified in and of itself but such persons would likely be screened for subclinical hypothyroidism and so those with subclinical hyperthyroidism identified. There are no controlled trials that show the benefit of treatment of subclinical hyperthyroidism, thus therapy at present needs to be determined by clinical judgement, aided by monitoring the patient to see if the low serum TSH level persists and assessing the presence or absence of other determinants of therapy such as an elevated serum triiodothyronine (T3) concentration, a multinodular goiter, or the appearance of overt symptoms.

Background: Both hypogonadism and low estrogen levels adversely affect bone health in young men. In elderly men, who are at greatest risk for osteoporotic fracture, the influence of hypogonadism on bone mineral density remains unclear, as does the relative effect of estrogen status compared to hypogonadism., Objective: To examine the relation of hypogonadism and estrogen status to bone mineral density in elderly men., Design: Community-based, prospective cohort study., Setting: Framingham, Massachusetts., Patients: Male participants of the Framingham Study., Measurements: Total testosterone, total estradiol, and luteinizing hormone were measured in participants at all four biennial examinations from 1981 to 1989. Values from at least three of four examinations were averaged. Hypogonadism was defined as a mean testosterone level less than 10.4 nmol/L (<3.0 ng/mL) or a mean luteinizing hormone level of 20 IU/L or greater. An alternate definition of hypogonadism based only on a mean testosterone level less than 10.4 nmol/L (<3.0 ng/mL) was also used. In 1988-1989, bone mineral density was measured at the proximal femur (femoral neck, Ward triangle, and trochanter) and lumbar spine by using dual-photon absorptiometry and at the radial shaft by using single-photon absorptiometry. The association of hypogonadism with bone mineral density was examined with adjustment for confounders, including estradiol levels. A similar model that adjusted for hypogonadism was used to examine the association of estradiol level (ranked as quartiles) with bone mineral density., Results: Of 448 men with bone mineral density measurements, 405 had evaluable hormone levels (mean age, 75.7 years [range, 68 to 96 years]); 71 (17.5%) of the 405 men were hypogonadal. Bone mineral density at any site did not significantly differ in hypogonadal men compared with eugonadal men (for example, bone mineral density at the femoral neck was 0.89 g/cm(2) vs. 0.87 g/cm(2), respectively; P > 0.2), even when alternate definitions of hypogonadism were used. In contrast, compared with the lowest estradiol quartile, men with higher estradiol levels had greater mean bone mineral density at all sites (for example, bone mineral density at the femoral neck was 0.84 g/cm(2), 0.88 g/cm(2), 0.86 g/cm(2), and 0.91 g/cm(2) from the lowest to the highest estradiol quartile; P for trend = 0.002). The difference in mean bone mineral density between men in the lowest and those in the highest estradiol quartile levels was similar to the effect of 10 years of aging on bone mineral density., Conclusions: In elderly men, hypogonadism related to aging has little influence on bone mineral density, but serum estradiol levels have a strong and positive association with bone mineral density.

Objective: The Veterans Affairs Cooperative Study in Type 2 Diabetes Mellitus (VA CSDM) was a multicenter randomized prospective study of 153 male type 2 diabetic patients to assess the ability to sustain clinically significant glycemic separation between intensive and standard treatment arms. A trend toward an excess of combined cardiovascular events in the intensive treatment arm of this trial was reported earlier. The present analysis was done to evaluate the effect of 2 years of intensive glycemic control on the left ventricular (LV) function., Research Design and Methods: The patients were randomized to intensive step treatment with insulin alone or with sulfonylurea (intensive treatment arm [INT], n = 75) or to standard once-daily insulin injection (standard treatment arm [STD], n = 78) treatment. A total of 136 patients (standard treatment arm [STD], n = 70; INT, n = 66) had radionuclide ventriculography at entry and at 24 months for the assessment of LV function., Results: There was no difference in the mean LV ejection fraction (at entry: STD 57.1+/-9.51%; INT 58.1+/-8.7%; at 24 months: STD 57.3+/-10.8%, INT 59.5+/-10.7%), peak filling rate (at entry: STD 2.6+/-0.7 end diastolic volume per second, INT 2.4+/-0.8 end diastolic volume per second; at 24 months: STD 2.7+/-1.0 end diastolic volume per second, INT 2.5+/-0.7 end diastolic volume per second), or time to peak filling rate (at entry: STD 195.3+/-69.5 ms, INT 185.6 +/-62.4 ms; at 24 months: STD 182.6+/-64.8 ms, INT 179.2+/-61.2 ms) between the 2 treatment arms. A subgroup analysis of 104 patients (STD, n = 53; INT, n = 51) that omitted individuals with intervening cardiac events/revascularization or a change in cardioactive medications also showed no difference in the LV function at entry and at 24 months between the 2 groups. Abnormal LV ejection fraction at baseline predicted cardiac events (interval between cardiac beats [RR] = 2.5)., Conclusions: Two years of intensive glycemic control does not affect the LV systolic or diastolic function in patients with type 2 diabetes.

To determine whether a difference in HbA(1c) could be safely sustained between a standard therapy (STD) arm and an intensive therapy (INT) arm, while maintaining HbA(1c) levels in both arms within a range acceptable in community practice. The effects of intensive treatment on various parameters were studied in this feasibility trial. We report here the results of 24 months of INT on peripheral and autonomic neuropathy.A prospective trial was conducted in five medical centers in 153 men of 60 +/- 6 years of age who had a known diagnosis of diabetes for 7.8 +/- 4 years. They were randomly assigned to a standard insulin treatment group (one morning injection per day) or to an intensive therapy group designed to attain near-normal glycemia and a clinically significant separation of glycohemoglobin from the standard arm. A four-step plan was used in the intensive therapy group along with daily self-monitoring of glucose: (1) an evening insulin injection, (2) the same injection adding daytime glipizide, (3) two injections of insulin alone, and (4) multiple daily injections. Peripheral neuropathy was diagnosed clinically by a history and physical examination, and by abnormal autonomic neuropathy Valsalva ratio (VR < 1.2) and RR variation (RRV < 10). An average HbA(1c) separation of 2.07% was achieved with INT, having HbA(1c) at or below 7.3% (p = 0. 001 versus STD). Baseline prevalence of peripheral neuropathy was 53% in STD, and 48% in INT. By 24 months, the prevalence increased to 69% in STD (p = 0.005 versus baseline), and to 64% in INT (p = 0. 008 versus baseline, but no different than STD). Though INT did not reverse all elements of peripheral neuropathy, there was a decreased prevalence of cranial neuropathy (p = 0.053 versus STD) and more frequent preservation of touch sensation in the upper extremities (p = 0.03 versus STD) in INT. At baseline, an abnormal Valsalva ratio and/or RR variation was seen in 38% of STD and 31% of INT. By 24 months in STD, the prevalence rose to 55% (p = 0.0067 versus baseline), and in INT, to 48% (p = 0.012 versus baseline and no different from STD). The prevalence of erectile dysfunction increased from 53% at baseline to 73% at 2 years, p = 0.002 in STD, and from 51% to 73% at 2 years (p = 0.003 versus baseline) and no different from STD. There was no change in the frequency of abnormal gastrointestinal or sweating symptoms. Our conclusion was that 2 years of meticulous glycemic control did not decrease overall prevalence of peripheral or autonomic neuropathy. In fact, the prevalence rose equivalently and significantly in both treatment arms. There was some benefit, however, in decreased frequency of cranial neuropathy and better preservation of touch sensation in INT.

Objective: The Veterans Affairs Cooperative Study in Type 2 Diabetes Mellitus was conducted in NIDDM patients to determine if a significant difference in HbA1c could be achieved between groups receiving standard and intensive treatment. We observed differences in the response to exogenous insulin between African-Americans and other intensively treated patients. Therefore, we assessed the variations of response and correlated factors that might explain such differences., Research Design and Methods: One hundred fifty-three men aged 40-69 years with NIDDM for < or = 15 years were randomized to either the standard therapy (n = 78) or the intensive therapy (n = 75) arm. Of the 75 patients in the intensive therapy group, 57 completed the study on insulin therapy alone. Of these, 18 were African-Americans and 39 were non-African-Americans. We conducted an analysis of the data collected to determine differences in baseline characteristics, glycemic response, insulin requirement, body weight, exercise, and basal C-peptide level, factors that may explain a difference in response to insulin therapy., Results: Glycemic control improved in all patients with intensive insulin therapy. African-Americans achieved a greater improvement in HbA1c compared with non-African-Americans with a similar increment in insulin. This difference could not be explained by differences in body weight, activity, concomitant use of other medicines, or insulin-secretory capacity of the pancreas., Conclusions: We conclude that ethnic differences may exist in the response to insulin therapy. A knowledge of such differences may aid in achieving good glycemic control, especially since minorities have a greater prevalence of and burden from the microvascular complications of diabetes.

There have been many theories regarding the origin or etiology of the peculiar disorder Robert James Graves first described in 1834. This article is a chronological discussion of the main ideas and the eras in which they were prominent, including the cardiac, neural, thyroid, pituitary, and modern eras.

Little was known about iodine metabolism in the mid-1930s, but when Saul Hertz and his chief, J. Howard Means, at the Massachusetts General Hospital (MGH) realized in 1936 that radioiodine could be made and used as a tracer, they arranged with physicists Robley Evans and Arthur Roberts at the Massachusetts Institute of Technology (MIT) to make the short-lived 128I and study its physiology in rabbits. By 1938, they showed that the rabbit's thyroid gland rapidly took up 128I, especially when there was only a little non-radioactive iodine present. There was, however, no hope of using 128I as a treatment because of its brief half-life (25 minutes). In 1939, Joseph Hamilton and Mayo Soley, working with Ernest Lawrence's cyclotron in Berkeley, California, were able to make several radioiodines; one was 130I (12-hour half-life) and another 131I (8-day half-life). They were the first to give these radioiodines to humans to study iodine physiology. The MGH-MIT group also built a cyclotron and by 1940 had generated these two new radioiodines. One of the goals of both groups was the treatment of hyperthyroidism. Hertz and Roberts were the first to do so on March 31, 1941; Hamilton and John Lawrence, Ernest's brother, began on October 12, 1941. By 1942, the United States was actively fighting in World War II. That year both Boston and Berkeley groups have preliminary data on the treatment of hyperthyroidism in Atlantic City; both showed that it was effective and went on to treat more patients. In Berkeley the therapy was viewed cautiously, and, in many case, the physicists were mainly occupied with work for the Manhattan District. In Boston Hertz used the therapy as often as he could, emphasizing the use of 130I, until he joined the U.S. Navy in 1943. Earle Chapman, a clinician on the voluntary staff of the MGH, took over Hertz's practice in 1943; their later differences over the precise treatment and who was in charge led to their falling out. After Hertz's release from the Navy he was not permitted to return to the MGH and became quite bitter; Chapman stayed on at the MGH. After the war was over, both had acquired a sufficient number of patients--there was then no such thing as a controlled trial--and wrote up the results for publication. Each wrote a different physicist, Hertz with Roberts and Chapman with Evans. When Hertz learned that Chapman's paper was being considered by the Journal of the American Medical Associations, he quickly sent his manuscript to JAMA as well. Although the editor of JAMA was puzzled by two papers on the same topic from the same institution, both papers appeared in the same issue of JAMA on May 11, 1964, and announced the new therapy was effective treatment for hyperthyroidism.

Objective: To estimate the cost-effectiveness of periodic screening for mild thyroid failure by measurement of serum thyroid stimulating hormone (TSH) concentration., Design: Cost-utility analysis using a state-transition computer decision model that accounted for case finding, medical consequences of mild thyroid failure, and costs of care during 40 years of simulated follow-up., Setting: Periodic health examinations in offices of primary care physicians., Patients: Hypothetical cohorts of women and men screened every 5 years during the recommended periodic examination, beginning at age 35 years., Interventions: Adding the serum TSH assay to total serum cholesterol screening was compared to cholesterol screening alone., Main Outcome Measures: Discounted quality-adjusted life years (QALYs) and direct medical costs from a societal perspective., Results: The cost-effectiveness of screening 35-year-old patients with a serum TSH assay every 5 years was $9223 per QALY for women and $22595 per QALY for men. The cost-effectiveness became more favorable when age at first screening was increased for both sexes and was always more favorable for women than men. Reduced progression to overt hypothyroidism and relief of symptoms increased QALYs, but did not substantially reduce direct medical costs. Finding hypercholesterolemia induced by mild thyroid failure reduced direct medical costs, but did not substantially increase QALYs. The cost of a TSH assay and the importance to patients of symptoms associated with thyroid failure were the most influential factors in sensitivity analyses., Conclusions: The cost-effectiveness of screening for mild thyroid failure compares favorably with other generally accepted preventive medical practices. Physicians should consider measuring serum TSH concentration in patients aged 35 years and older undergoing routine periodic health examinations. The cost-effectiveness of screening is most favorable in elderly women.

In 1936, Karl Compton, then president of the Massachusetts Institute of Technology (MIT) and the thyroid group of the Massachusetts General Hospital (MGH), undertook a joint study that led to the production of small amounts of short-lived radioiodine (iodine 128, half-life, 25 min). The original intent was to use it for diagnosis and treatment of thyroid disease, but in order to explore the underlying physiology, their first work was performed in rabbits and published in 1938. It clearly showed that the radioiodine was selectively and avidly taken up by the thyroid gland. It was immediately apparent to the MGH-MIT group and another team working at the Berkeley, CA cyclotron that longer-lasting iodine isotopes were needed, and soon both developed procedures for cyclotron-produced 130 (half-life, 12.5 hr) and 131I (half-life, 8 d). In 1939, the Berkeley group, using 131I, was the first to show that the normal human thyroid gland accumulated radioiodine. By 1941, the MGH-MIT team, using mainly 130I, was able to successfully treat a few patients with hyperthyroidism, and so achieved their original goal. The Berkeley group did the same a few months later, using mainly 131I. Both presented results at the same meeting of the American Society for Clinical Investigation in Atlantic City, NJ in the spring of 1942. This was in the midst of World War II and it was not easy to get much 130I or 131I, so experience was limited. Although effective, radioiodine treatment of hyperthyroidism had not been widely adopted by the end of the war in 1945, partly because radioiodine remained in short supply and partly because another medical therapy for hyperthyroidism, antithyroid drugs, had been invented. However, by 1946, fission-derived radioiodine became readily available as a by-product of the Manhattan project in Oak Ridge, TN; hundreds of patients were treated within a few years, both for hyperthyroidism and for thyroid cancer. A new treatment, based on the physiological application of a radioisotope of iodine, was then a reality.

Objective: To assess whether current thyroid status is associated with chondrocalcinosis or osteoarthritis (OA), we examined the cross sectional association of serum thyrotropin (thyroid stimulating hormone, TSH) with chondrocalcinosis and with knee OA in members of the Framingham OA study., Methods: Knee radiographs were taken at the 18th biennial examination (1983-85) and measurement of serum TSH at either the 15th (1977-79) or the 18th biennial examination. Chondrocalcinosis was dichotomized as absent or present and knee OA was based on a Kellgren and Lawrence score of grade 2 or greater in either knee. Thyroid status was determined by serum TSH concentration classed into clinically relevant categories: < or = 0.1 mU/l(low); > 0.1 < 0.4 mU/l (slightly low); 0.4 to 5.0 mU/l (normal); > 5 < or = 10 mU/l (slightly high); and > 10 mU/l (high)., Results: Data were collected on 577 men and 798 women. We found no association between elevated serum TSH concentration and chondrocalcinosis. Our results, though not statistically significant, suggest an inverse relation, with an odds ratio (OR) of 0.41 (95% CI 0.10, 1.73) for those subjects. in the highest TSH group and 1.79 (95% CI 0.39, 8.24) for those in the lowest TSH group, compared to subjects in the normal range. We found no association between serum TSH concentration and radiographic knee OA, with an OR of 0.85 (95% CI 0.47, 1.51) for those in the highest serum TSH group and 1.51 (95 CI 0.54, 4.22) for those in the lowest TSH group, compared to the normal group. Exclusion of subjects taking thyroid hormone confirmed these null results., Conclusion: There was no evidence, in a large unselected population of older persons, of a significant association between current thyroid status and either chondrocalcinosis or OA.

Because subclinical hypothyroidism is common (4%-8% of people older than 60 years of age), has some clinical consequences, and is easily and safely treated, screening of older persons is justified. Diagnosis depends on showing a raised serum TSH (less than 10 mU/L), a test that will cost less in the near future. There are, however, still some uncertainties about this condition, and supportive data are not perfect. Better studies are essential to help define clinical practice.

Background: Low serum thyrotropin concentrations are a sensitive indicator of hyperthyroidism but can also occur in persons who have no clinical manifestations of the disorder. We studied whether low serum thyrotropin concentrations in clinically euthyroid older persons are a risk factor for subsequent atrial fibrillation., Methods: We studied 2007 persons (814 men and 1193 women) 60 years of age or older who did not have atrial fibrillation in order to determine the frequency of this arrhythmia during a 10-year follow-up period. The subjects were classified according to their serum thyrotropin concentrations: those with low values (< or = 0.1 mU per liter; 61 subjects); those with slightly low values (> 0.1 to 0.4 mU per liter; 187 subjects); those with normal values (> 0.4 to 5.0 mU per liter; 1576 subjects); and those with high values (> 5.0 mU per liter; 183 subjects)., Results: During the 10-year follow-up period, atrial fibrillation occurred in 13 persons with low initial values for serum thyrotropin, 23 with slightly low values, 133 with normal values, and 23 with high values. The cumulative incidence of atrial fibrillation at 10 years was 28 percent among the subjects with low serum thyrotropin values (< or = 0.1 mU per liter), as compared with 11 percent among those with normal values; the age-adjusted incidence of atrial fibrillation was 28 per 1000 person-years among those with low values and 10 per 1000 person-years among those with normal values (P = 0.005). After adjustment for other known risk factors, the relative risk of atrial fibrillation in elderly subjects with low serum thyrotropin concentrations, as compared with those with normal concentrations, was 3.1 (95 percent confidence interval, 1.7 to 5.5; P < 0.001). The 10-year incidence of atrial fibrillation in the groups with slightly low and high serum thyrotropin values was not significantly different from that in the group with normal values., Conclusions: Among people 60 years of age or older, a low serum thyrotropin concentration is associated with a threefold higher risk that atrial fibrillation will develop in the subsequent decade.

Objective: To determine whether serum thyrotropin (TSH) levels are altered in euthyroid older persons compared with middle-aged adults., Design: Serum TSH and thyroid hormone levels were measured in a large group of older persons (> 70 years old, n = 216) and their middle-aged offspring (40-60 years old, n = 211) after excluding those with clinical or historical evidence of thyroid disease or abnormal thyroid function., Measurements: Serum TSH, thyroxine (T4), free T4 index, estimated free T4, triiodothyronine (T3), estimated free T3, and ferritin levels were measured on the Abbott IMx instrument. Peroxidase and thyroglobulin antibodies were measured by radioimmunoassay using Kronus kits., Main Results: Overall, serum TSH showed a log-normal distribution. The geometric mean TSH (mU/L) and 95% confidence limits in the older persons, 1.24 (0.29-5.4), did not differ significantly from that in the middle-aged, 1.45 (0.54-3.9). The mean TSH in the 264 women, 1.37 (0.34-5.5), was similar to that of the 163 men, 1.30 (0.48-3.5). The mean TSH in older women, 1.21 (0.22-6.6), was slightly but significantly lower than that in middle-aged women, 1.52 (0.55-4.2). However, when euthyroid women with positive antibodies were excluded, this difference was not significant. Four of the 123 older women had TSH < 0.1 mU/L, but none of the men or middle-aged women had a suppressed serum TSH. The mean TSH in older men, 1.28 (0.43-3.8), was similar to that in middle-aged men, 1.32 (0.55-3.2). Free T4 was slightly higher in older women than middle-aged women. There were no significant correlations between TSH and any thyroid hormone level. Serum ferritin, measured as a potential marker for the action of thyroid hormone, did not correlate with any measure of thyroid function. At least one antibody level was > 10 U/mL in 14.6% of older women, 15.6% of middle-aged women, 4.3% of older men, and no middle-aged men. When those with milder elevations of antibody levels were included (at least one level > 1 U/mL), the prevalence was 32% of older women, 43.3% of middle-aged women, 15% of older men, and 11.4% of middle-aged men., Conclusions: Euthyroid older persons have about the same levels of serum TSH as younger ones, although older euthyroid women have a slightly lower serum TSH than middle-aged women. We recommend that the normal range of serum TSH in the elderly be considered to be the same as that in healthy middle-aged subjects.

We studied a large population (n = 2575) of unselected ambulatory persons older than 60 years to determine the prevalence of a low serum thyroid-stimulating hormone (TSH) level, ie, of less than 0.1 mU/L using a sensitive assay, a level suggestive of hyperthyroidism in younger adults. One hundred one persons (3.9%) had a low serum TSH level. About half of them (51/101) were taking thyroid hormone. Of the remainder, 44 were not hyperthyroid did not become so during up to 4 years of follow-up. Forty-one of the 44 euthyroid persons had a serum thyroxine level of less than 129 nmol/L; repeated testing showed a serum TSH level of more than 0.1 mU/L in the three euthyroid persons with a serum thyroxine level of more than 129 nmol/L. Only six were hyperthyroid or became so during the follow-up period; all had a serum thyroxine level of more than 129 nmol/L. Routine clinical examination was not a sensitive indicator of hyperthyroidism and did not permit discrimination from euthyroidism. A low value of serum TSH alone, while it had high sensitivity and specificity for hyperthyroidism, had a low positive predictive value (12%) for this diagnosis; addition of the thyroxine assay raised the predictive value fivefold to 67%. A low value of serum TSH is far more common in older persons than is hyperthyroidism. Low values in euthyroid persons are accompanied by a clearly normal serum T4 concentration (less than 129 nmol/L) or by a serum TSH level of more than 0.1 mU/L on repeated testing. We recommend measurement of the serum TSH thyroid concentration, using a sensitive assay, as the initial step in testing any older person for possible hyperthyroidism. Measurement of the serum T4 concentration or the free T4 index on the same sample would be needed only in the approximately 2% with a serum TSH level of less than 0.1 mU/L; alternatively, the TSH assay in these could be repeated at a later time.

In an unselected population of elderly (over age 60 years) men and women (the original cohort of the Framingham Study), the prevalence of thyroid deficiency, evidenced by a clearly elevated serum thyrotropin (TSH) level (greater than 10 microU/mL), was 4.4%. Women had thyroid deficiency (5.9%) more often than men (2.3%). Of those with clearly elevated serum TSH levels, only 39% had low serum thyroxine (T4) levels; the remainder had serum T4 levels in the lower half of the normal range. Others (5.9%) had a slightly elevated serum TSH level (5 to 10 microU/mL); their status was not clear, but more (12.7%) had low T4 levels than expected. The level of serum T4 was not a sensitive measure of thyroid deficiency nor was routine examination by a physician, even when the patient's background contained a clue to a possible thyroid problem. An elevated serum TSH level was a sensitive marker of thyroid deficiency in the elderly and was often the only way to detect it. Further studies are needed to determine the relationship of thyroid deficiency to cognitive and cardiovascular function in older persons.

In 84 patients, aged 23 to 84, with primary hypothyroidism, the daily dose of thyroxine needed to lower the serum thyrotropin level into the normal range was significantly less in older patients than in younger ones (p less than 0.01). Most of the difference between middle-aged (40 to 60 years) and older patients (greater than 60 years) was due to a decrease in the required dose in men; there was no difference in the dose needed by women in these age groups. Previous hyperthyroidism did not affect the dose of thyroxine required; it is unlikely that residual autonomous thyroid tissue affected the dose. Although the wide range of doses needed precludes use of these data in calculating a dose of thyroxine for an individual patient, doses of 100 micrograms per day or less were common in patients over age 40, and a few patients over age 60 needed 50 micrograms per day or less. Thus, (1) there is a sound physiologic basis for the common practice of using low doses of thyroxine, e.g., 25 micrograms per day, as initial therapy in older hypothyroid patients and (2) it may be reasonable to reassess the dose of thyroxine after several years in older patients.

We studied basal serum prolactin in older (greater than age 50) men (N = 501) and women (N = 384) using younger adults for comparison and excluding those taking medications. Serum prolactin rose slightly with increasing age in men; it fell slightly in women until age 80, when it rose slightly. Men and women were not different except for the higher value in women at age 20 to 29. Serum prolactin did not fall after the menopause, while estrogen treatment had no effect on older women and caused only a slight rise in older men. Thyroid deficiency had only a minimal effect and did not raise the serum prolactin above 25 ng/ml. The prevalence of clearly elevated values (greater than 20 ng/ml) was only 1.3% in women and 0.6% in men above age 50; there is little evidence for a significant prevalence of prolactin-secreting adenomata in older persons. In older persons, prolactin-secreting tumors are uncommon, and neither thyroid failure nor estrogen therapy are good explanations for a clearly elevated serum prolactin.

Unlabelled: The mean (+/- SE) peak level of serum growth hormone (GH) after intramuscular injection of glucagon in ten normal adult men was 15.1 +/- 2.1 ng/ml; glucose infusion suppressed the mean peak GH to 9.6 +/- 3.7 ug/ml (p less than 0.05). Pretreatment of eight of these subjects with propranolol caused a modest increase in the mean peak GH after glucagon (19.4 +/- 2.8 ng/ml) but did not improve the mean peak GH after glucagon when glucose was infused (8.7 +/- 2.8 ng/ml). Individual analysis of the peak GH showed that glucose infusion did not uniformly suppress the peak GH after glucagon; in seven subjects the peak GH was suppressed but in three it was not., Conclusions: (1) The GH response after glucagon is usually due to a fall in serum glucose after the initial rise in serum glucose induced by glucagon. (2) Nevertheless, since glucose does not consistently inhibit the GH response after glucagon, a second mechanism probably exists by which glucagon stimulates GH secretion. (3) Glucose completely suppresses the propranolol-induced increase in the GH response to glucagon; an adrenergic mechanism may be involved in the control of GH secretion by glucose.

Seven patients with clinically active acromegaly who had not responded completely to previous surgical or radiation therapy were treated with bromocriptine. Bromocriptine was well tolerated; only one of the seven patients discontinued treatment secondary to side effects. Six of the seven patients improved during bromocriptine therapy, although GH levels were normalized in only two patients. All patients had elevated levels of somatomedin C (Sm-C) before therapy even when basal levels of GH were less than 10 ng/ml. One patient normalized both GH and Sm-C during bromocriptine therapy and had an excellent clinical response. Five patients had moderately good clinical responses; four of these patients had substantial falls in GH levels, but Sm-C levels fell minimally if at all in four and actually increased in one patient. In one patient, there was no change in clinical status, GH levels, or Sm-C levels. Thus, the clinical response did not correlate well with changes in Sm-C in most patients. The patterns of response to provocative stimuli of GH secretion in acromegaly were maintained during bromocriptine therapy, as has been previously been reported. Based on our experience, bromocriptine appears to be a useful adjunct in the therapy of acromegaly, even in patients who have had prior ablative therapy.

Thirty-two patients with primary hypothyroidism were given oral thyroxine as Levothroid or Synthroid to see if the two preparations had similar effects. The serum thyroxine was used as an index of bioavailability and the serum thyrotrophin as an index of biologic activity. The serum thyroxine was lower in all 32 patients when taking Synthroid than when taking Levothroid. In 15 patients the serum thyroxine level fell low enough to raise the serum thyrotrophin; in all 15 the serum thyrotrophin rose when taking Synthroid. Direct measurement of thyroxine in the tablets showed that the tablets of Synthroid contained 20% to 30% less thyroxine than their stated content. Thus, the decreased bioavailability (lower serum thyroxine) and decreased biologic action (higher serum thyrotrophin) of Synthroid were due to the lower content of thyroxine. An incidental observation is that the range of serum thyroxine in treated hypothyroid patients is 7.6 to 16.6 micrograms/dL, higher than in normal persons. Because oral thyroxine is widely used, a cooperative effort among manufacturers, the United States Pharmacopeia and Food and Drug Administration, and clinicians to ensure the potency and biologic action of oral thyroxine is in order. Meanwhile, it seems reasonable to use oral thyroxine that is close to the stated content.

The effect of graded increments of chronically administered oral T4 or T3 on the TSH response to TRH was studied in normal young adult men. The TSH response was assessed in the baseline state and after each increment of each hormone (two weeks at each dose level) using both 30 mug and 500 mug doses of TRH. Each thyroid hormone caused a dose-related decrease in the TSH response to TRH; thus the TSH response could be used as a bioassay for the biologic activity of the thyroid hormones in man. The dose of thyroid hormone that caused a 50% suppression of the TSH response, or the SD50, was not different with either 30 mug or 500 mug of TRH indicating that thyroid hormone suppression of the TSH response is not more easily detected with a small dose of TRH. The mean SD50 for T4 was 115 mug/day, for T3 stopped 2 h before testing the mean SD50 was 29 mug/day, and for T3 stopped 24 h before testing it was 45 mug/day. Using the average SD50 for the two T3 regimens (37 mug/day), the calculated relative potency indicates that oral T3 is 3.3 times as potent as oral T4, a value in reasonable agreement with the value previously estimated with a calorigenic end-point. The mean dose of T4 needed to decrease the TSH response to TRH to below the normal range (max delta TSH of 2 muU/ml) was 150 mug/day; this value is probably more appropriate than the SD50 in the treatment of patients with primary hypothyroidism or goiter and was about the same (160 mug/day) using a peak TSH after TRH of 3 muU/ml as an end-point. Estimation of the SD50 in each subject showed a 2- to 3-fold range with all regimens of thyroid hormones; similarly there was a 2-fold in the dose of T4 needed to suppress the TSH response to TRH to below the normal range. Further, the difference in the mean SD50 for the two T3 regimens indicates that a single daily dose of oral T3 does not exert a constant biologic effect throughout the day. Thus, because of individual variation and, in the case of T3, because of changing activity during the day a given dose of thyroid hormone may have a widely varying biologic effect. There was also a 3-fold range in the relative potency of T3 to T4 in the four subjects treated with both hormones. This suggests that the therapeutic administration of a fixed ratio fo T3 to T4 may have a variable effect from patient to patient. Finally, the serum T4 rose while the serum T3 did not at a dose of T4 that abolished the TSH response to TRH, indicating that circulating T4 is a determinant of TSH secretion in normal man.

Fluoxymesterone, an androgen not converted to estrogen, caused a significant decrease in the TSH response to TRH in 11 men with primary hypogonadism [maximum change in TSH: before treatment, 11.3 +/- microU/ml (mean +/- SE); 8.9 +/- 1.0 after 2 weeks (P less than 0.001); 8.2 +/- 1.1 after 6 weeks (P less than 0.01)]. There was a significant fall in serum T4-binding globulin (TBG) (measured directly by RIA) without a change in the free T4 or free T3 index. Fluoxymesterone had no effect on the PRL response to TRH in hypogonadal men. The results suggest that 1) androgen per se is at least partly responsible for the lower TSH response to TRH in men compared to women and 2) androgen is not a cause of the lower PRL response to TRH in men.

Basal serum TSH and the peak TSH response to a 500 micrograms TRH bolus were measured in 57 euthyroid and in 29 hypothyroid subjects either receiving graded thyroid hormone replacement or acutely removed from full replacement therapy. Serum TSH, total T4 and T3 were determined by sensitive radioimmunoassay methods. The peak versus basal TSH data for hypothyroid patients were linear within individuals. The regression slope of the peak versus basal TSH data for all hypothyroid subjects did not differ significantly from the corresponding slope for all euthyroid subjects. Basal and peak TSH versus T3 and T4 data for hypothyroid patients were also linear within each individual. Moreover, the regression of the basal TSH values averaged over the non-replacement to full replacement state against the TSH versus T3 slope had a significant negative correlation. This trend leads to an array of regression lines which average to the familiar hyperbolic relationship between thyrotrophin and thyroid hormone levels in man.

Large doses of iodide (500 mg three times a day) administered to normal men for 10--12 days caused a rise in basal serum TSH and a concomitant rise in the peak TSH response to TRH. The basal and peak levels of TSH were highly correlated (p less than 0.001). However, the iodide-induced rise in the peak TSH after TRH was poorly correlated with concomitant changes in serum thyroid hormones. Serum T3 wa not lower after iodide and, while serum T4 was somewhat lower, the fall in serum T4 was unexpectedly inversely rather than directly correlated with the rise in the peak TSH response to TRH. Thus, increased TSH secretion after iodide need not always be directly correlated with decreased concentrations of circulating thyroid hormones even when large doses of iodide are used. Clinically, a patient taking iodide may have an increased TSH response in a TRH stimulation test even though there is little or no change in the serum level of T3 or T4.

Fasting hypoglycemia occurred in a patient with a histologically benign mesothelioma; the serum insulin was low (2-4 muU./ml.), as was the glucose utilization rate. Splanchnic glucose output was markedly decreased on direct measurement (21 mg./min.; normal: 108-180 mg./min.). Splanchnic uptake of gluconeogenic substrates plasma glucagon was low normal during hypoglycemia and responded poorly to oral and intravenous alanine. The nonsuppressible insulin-like (NSILA-s) and somatomedin-like activities of the serum were not elevated, and the tumor did not release insulin-like activity on incubation nor did it contain somatostatin. The marked decrease in splanchnic glucose output was the principal cause of hypoglycemia, was associated with an apparent decrease in glycogenolysis, and was at least partly due to deficient glucagon secretion. The relationship of the tumor to these defects is unclear. The tumor may have secreted an unknown insulin-like material affecting primarily the liver and/or pancreatic alpha cell. The approach used here may serve as a paradigm for the analysis of hypoglycemia not caused by excessive insulin.