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Changes in women’s menstrual bleeding patterns precede the onset of menopause. In this paper, the authors identify population subgroups based on menstrual characteristics of the menopausal transition experience. Using the TREMIN data set (1943–1979), the authors apply a Bayesian change-point model with 8 parameters for each woman that summarize change in menstrual bleeding patterns during the menopausal transition. The authors then use estimates from this model to classify menstrual patterns into subgroups using a K-medoids algorithm. They identify 6 subgroups of women whose transition experience can be distinguished by age at onset, variability of the menstrual cycle, and duration of the early transition. These results suggest that for most women, mean and variance change points are well aligned with proposed bleeding markers of the menopausal transition, but for some women they are not clearly associated. Increasing understanding of population differences in the transition experience may lead to new insights into ovarian aging. Because of age inclusion criteria, most longitudinal studies of the menopausal transition probably include only a subset of the 6 subgroups of women identified in this paper, suggesting a potential bias in the understanding of both the menopausal transition and the linkage between the transition and chronic disease. [ABSTRACT FROM PUBLISHER]

A population-based case-control study of renal cell cancer was conducted in Minnesota between 1988 and 1990. it included 690 historically confirmed incident cases identified through the state cancer surveillance system, and 707 age and sex frequency-matched controls. In this paper, the authors present estimates of the proportion of renal cell cancer cases attributable (or population attributable risk (PAR)) to 1) well-established risk factors, namely smoking, excess weight, and hypertension, and 2) more speculative risk factors, namely elevated protein intake, history of renal disease (i.e., stone, injury, or infection) and high parity among women. These estimates were based on information obtained from directly interviewed subjects (65% of cases and 100% of controls). The PARs for the three main risk factors were 21 % for hypertension (defined by a reported personal history of hypertension or of treatment with antihypertensive or diuretic drugs), 21% for excess weight (defined by an elevation of the usual body mass index above the first quartile), and 18% for smoking (past and current). Overall, these three factors accounted for 49% of cases. The proportion increased to 60% when the three more speculative risk factors were considered as well. Sex-specific analyses revealed a greater impact of smoking among men mainly due to a higher prevalence of past smoking. In contrast, the impact of hypertension and excess weight was greater among women due to higher relative risks. These results suggest that 1) intervention measures aimed at reducing smoking, excess weight, and hypertension could substantially lower the overall incidence of renal cell cancer, and 2) intervention measures may have to be sex-specific. Conversely, because at least 40% of cases remain unexplained by the risk factors under study, further etiologic research is needed into renal cell cancer, an increasingly common form of cancer. Am J Epidemiol 1998; 148: 424–30. [ABSTRACT FROM AUTHOR]

In this paper, the authors report trends in hospitalized stroke rates among Minneapolis-St. Paul, Minnesota (population 2.6 million) metropolitan area residents aged 30–74 years from 1980 to 2000. Cases were identified from lists of discharge diagnoses provided by hospitals serving the target population. Age-adjusted, sex-specific stroke attack rates were computed for each survey year by using 5 different diagnostic definitions: 2 based purely on International Classification of Diseases, Ninth Revision (ICD-9) codes and 3 including clinical and neuroimaging criteria. Stroke rates, as measured by a highly specific clinical definition, remained stable from 1980 to 2000 for women. For men, these rates declined modestly from 1980 to 1990 and leveled off during 1990–2000. In contrast, use of stroke-related ICD-9 discharge codes declined significantly from 1980 to 2000: 35% among men and 16% among women. Neuroimaging use increased significantly from 75% of cases in 1980 to 98% in 2000. Short-term (28-day) stroke survival improved significantly, by 16% for women and 12% for men, from 1980 to 2000. The decline in stroke ICD-9 code usage reflects the influence of increased neuroimaging on discharge coding. The improved short-term survival in the face of stable, clinically defined stroke rates may imply treatment advances or ascertainment of less severe strokes, possibly masking a true decline in stroke rates. [ABSTRACT FROM AUTHOR]

Experiences of discrimination are associated with increased risk of adverse health outcomes; however, it is unknown whether discrimination is related to incident type 2 diabetes mellitus (diabetes). We investigated the associations of major experiences of discrimination (unfair treatment in 6 situations) and everyday discrimination (frequency of day-to-day experiences of unfair treatment) with incident diabetes among 5,310 participants from the Multi-Ethnic Study of Atherosclerosis, enrolled in 2000-2002. Using Cox proportional hazards models, we estimated hazard ratios and confidence intervals, adjusting for demographic factors, depressive symptoms, stress, smoking, alcohol, physical activity, diet, waist circumference, and body mass index. Over a median follow-up of 9.4 years, 654 diabetes cases were accrued. Major experiences of discrimination were associated with greater risk of incident diabetes when modeled continuously (for each additional experience of discrimination, hazard ratio = 1.09, 95% confidence interval: 1.01, 1.17) or categorically (for ≥2 experiences vs. 0, hazard ratio = 1.34, 95% confidence interval: 1.08, 1.66). Similar patterns were observed when evaluating discrimination attributed to race/ethnicity or to a combination of other sources. Everyday discrimination was not associated with incident diabetes. In conclusion, major experiences of discrimination were associated with increased risk of incident diabetes, independent of obesity or behavioral and psychosocial factors. Future research is needed to explore the mechanisms of the discrimination- diabetes relationship. [ABSTRACT FROM AUTHOR]

Prospective cohort studies are needed to assess the relationship between the fecal microbiome and human health and disease. To evaluate fecal collection methods, we determined technical reproducibility, stability at ambient temperature, and accuracy of 5 fecal collection methods (no additive, 95% ethanol, RNAlater Stabilization Solution, fecal occult blood test cards, and fecal immunochemical test tubes). Fifty-two healthy volunteers provided fecal samples at the Mayo Clinic in Rochester, Minnesota, in 2014. One set from each sample collection method was frozen immediately, and a second set was incubated at room temperature for 96 hours and then frozen. Intraclass correlation coefficients (ICCs) were calculated for the relative abundance of 3 phyla, 2 alpha diversity metrics, and 4 beta diversity metrics. Technical reproducibility was high, with ICCs for duplicate fecal samples between 0.64 and 1.00. Stability for most methods was generally high, although the ICCs were below 0.60 for 95% ethanol in metrics that were more sensitive to relative abundance. When compared with fecal samples that were frozen immediately, the ICCs were below 0.60 for the metrics that were sensitive to relative abundance; however, the remaining 2 alpha diversity and 3 beta diversity metrics were all relatively accurate, with ICCs above 0.60. In conclusion, all fecal sample collection methods appear relatively reproducible, stable, and accurate. Future studies could use these collection methods for microbiome analyses. [ABSTRACT FROM AUTHOR]

Although rates of incident dementia have been reported from several populations, the impact of nonparticipation on dementia incidence in studies of cognitive aging is unknown. In 2004, investigators with the Mayo Clinic Study of Aging selected persons aged 70–89 years from an enumeration of all Olmsted County, Minnesota, residents (age- and sex-stratified random sample). Of 4,398 potential participants, 2,050 agreed to undergo an in-person health assessment. Those participants were reevaluated in person using standard diagnostic procedures approximately every 15 months over a median follow-up period of 5.7 years (through September 15, 2013). There were 1,679 persons who refused any participation. A trained nurse abstractor reviewed the medical records of nonparticipants using the Rochester Epidemiology Project's medical record linkage system a median of 3.9 years after refusal. Nonparticipants had a higher prevalence of dementia than participants evaluated in person (6.5% vs. 3.3%; P < 0.0001). The standardized incidence of dementia was not significantly higher among the nonparticipants (23.2 per 1,000 person-years) than in those evaluated in person (19.6 per 1,000 person-years; hazard ratio = 1.17, 95% confidence interval: 0.95, 1.43 (P = 0.13); adjusted for education and sex, with age as the time scale). The small, nonsignificant impact of nonparticipation on rates of incident dementia is reassuring for future studies based on incident dementia cases. [ABSTRACT FROM PUBLISHER]

Accurate rates of herpes zoster incidence and complication have become of greater interest as studies have suggested an increasing temporal trend in incidence rates across all age groups and long-term follow-up studies of vaccine effectiveness are required by the Food and Drug Administration. This study compares the results obtained from the most commonly used method to obtain herpes zoster data (rates obtained from administrative data) with results obtained when administrative data are supplemented by medical record review. Administrative billing code data identified 1,959 cases of herpes zoster in Olmsted County, Minnesota, adults between January 1, 1996, and December 31, 2001. Of those 1,959 cases, 1,669 (85.2%) could be confirmed by medical record review, a decrease in incidence rate of 14.8%, resulting in a decrease of 0.61/1,000 person-years when adjusted to the US adult population. Complication rates were also significantly different between the 2 methods. It is not clear if the 15% decrease in incidence rates would be seen in every administrative data set or if the lack of confirmation of cases may be variable in both validity and reproducibility between data sets, making estimations in temporal trends and pre/post-vaccine rates difficult to compare across data resources. [ABSTRACT FROM AUTHOR]

Functional biomarkers like large artery elasticity (LAE) and small artery elasticity (SAE) may predict cardiovascular disease (CVD) events beyond blood pressure. The authors examined the prognostic value of LAE and SAE for clinical CVD events among 6,235 Multi-Ethnic Study of Atherosclerosis participants who were initially aged 45–84 years and without symptomatic CVD. LAE and SAE were derived from diastolic pulse contour analysis. During a median 5.8 years of follow-up between 2000 and 2008, 454 adjudicated CVD events occurred, including 256 cases of coronary heart disease (CHD), 93 strokes, and 126 heart failures (multiple diagnoses were possible). After adjustment for age, race/ethnicity, sex, clinic, height, heart rate, body mass index, systolic and diastolic blood pressure, use of antihypertensive and cholesterol-lowering medications, smoking, total cholesterol, high density lipoprotein cholesterol, triglycerides, diabetes, and high-sensitivity C-reactive protein, the hazard ratio for any CVD per standard-deviation increase in SAE was 0.71 (95% confidence interval: 0.61, 0.83; P < 0.0001). The lowest (stiffest) SAE quartile had a hazard ratio of 2.28 (95% confidence interval: 1.55, 3.36) versus the highest (most elastic) quartile. The net reclassification index, conditional on base risk, was 0.11. SAE was significantly associated with future CHD, stroke, and heart failure. After adjustment, LAE was not significantly related to CVD. In asymptomatic participants free of overt CVD, lower SAE added prognostic information for CVD, CHD, stroke, and heart failure events. [ABSTRACT FROM PUBLISHER]

The Rochester Epidemiology Project (REP) is a unique research infrastructure in which the medical records of virtually all persons residing in Olmsted County, Minnesota, for over 40 years have been linked and archived. In the present article, the authors describe how the REP links medical records from multiple health care institutions to specific individuals and how residency is confirmed over time. Additionally, the authors provide evidence for the validity of the REP Census enumeration. Between 1966 and 2008, 1,145,856 medical records were linked to 486,564 individuals in the REP. The REP Census was found to be valid when compared with a list of residents obtained from random digit dialing, a list of residents of nursing homes and senior citizen complexes, a commercial list of residents, and a manual review of records. In addition, the REP Census counts were comparable to those of 4 decennial US censuses (e.g., it included 104.1% of 1970 and 102.7% of 2000 census counts). The duration for which each person was captured in the system varied greatly by age and calendar year; however, the duration was typically substantial. Comprehensive medical records linkage systems like the REP can be used to maintain a continuously updated census and to provide an optimal sampling framework for epidemiologic studies. [ABSTRACT FROM AUTHOR]

The authors compared trends in and levels of coronary heart disease (CHD) risk factors between the Minneapolis-St. Paul, Minnesota, metropolitan area (Twin Cities) and the entire US population to help explain the ongoing decline in US CHD mortality rates. The study populations for risk factors were adults aged 25–74 years enrolled in 2 population-based surveillance studies: the Minnesota Heart Survey (MHS) in 1980–1982, 1985–1987, 1990–1992, 1995–1997, and 2000–2002 and the National Health and Nutrition Examination Survey (NHANES) in 1976–1980, 1988–1994, 1999–2000, and 2001–2002. The authors found a continuous decline in CHD mortality rates in the Twin Cities and nationally between 1980 and 2000. Similar decreasing rates of change in risk factors across survey years, parallel to the CHD mortality rate decline, were observed in MHS and in NHANES. Adults in MHS had generally lower levels of CHD risk factors than NHANES adults, consistent with the CHD mortality rate difference. Approximately 47% of women and 44% of men in MHS had no elevated CHD risk factors, including smoking, hypertension, high cholesterol, and obesity, versus 36% of women and 34% of men in NHANES. The better CHD risk factor profile in the Twin Cities may partly explain the lower CHD death rate there. [ABSTRACT FROM PUBLISHER]

The association between psychosocial risk factors and retinal microvascular signs was examined in the Multi-Ethnic Study of Atherosclerosis. Subjects were recruited from Baltimore, Maryland; Chicago, Illinois; Forsyth County, North Carolina; Los Angeles County, California; New York, New York; and St. Paul, Minnesota. Levels of depressive symptoms, trait anger, trait anxiety, chronic burdens, emotional support, and cynical distrust were assessed by questionnaire (from July 2000 to July 2002). Digital retinal images (from August 2002 to January 2004) from 6,147 participants were used to evaluate retinopathy and retinal vascular caliber. After controlling for potential confounding factors, the authors found that subjects without access to emotional support (Enriched Social Support Instrument score of <19 vs. ≥19) had 60% greater odds of retinopathy (odds ratio = 1.6, 95% confidence interval (CI): 1.3, 2.0). Subjects with high Spielberger trait-anxiety scale scores (≥22 vs. ≤14) and subjects with high depressive symptoms (Center for Epidemiology Studies Depression Scale score, ≥16 vs. <16) were also more likely to have retinopathy (odds ratio = 1.4, 95% CI: 1.1, 1.9 and odds ratio = 1.5, 95% CI: 1.2, 1.9), respectively. In this cross-sectional study, lack of emotional support, increased trait anxiety, and more depressive symptoms were associated with retinopathy signs, independently of other known risk factors. [ABSTRACT FROM PUBLISHER]

Long-term trends in epidemiologic studies of acute myocardial infarction (AMI) require application of a consistent diagnostic algorithm. Typically an algorithm includes chest pain, cardiac enzymes, electrocardiographic findings, and autopsy results. The Minnesota Heart Survey (MHS) has determined trends for incident AMI and for in-hospital and long-term outcomes over a 25-year period (1970–1995). However, dramatic changes have occurred that seriously challenge the ability of the MHS and other epidemiologic studies to use a consistent diagnostic algorithm. These include newer and more sensitive cardiac biomarkers, introduction of diagnosis-related groups, and change in International Classification of Diseases coding. In the MHS, the electrocardiogram is the only diagnostic element consistently available and consistently classified over this 25-year period. The authors identified eight dichotomous Minnesota Code criteria that provided a consistent diagnostic method from 1970 to 1995 as documented by extensive cross-validation. These criteria were combined into a logistic score and used to define incident, recurrent, and attack AMI rates over this 25-year period. For both men and women, AMI rates determined by electrocardiogram are parallel to rates based on the International Classification of Diseases and parallel over adjacent survey periods to the standard MHS algorithm. The electrocardiogram classified by Minnesota Code provides the only consistent long-term diagnostic tool for AMI trends over this 25-year period. [ABSTRACT FROM PUBLISHER]

The association between androgen receptor gene polymorphisms and benign prostatic hyperplasia was investigated among 510 men randomly selected from Olmsted County, Minnesota. From 1990 through 2000, lower urinary tract symptom severity was assessed by the American Urological Association Symptom Index (AUASI), and peak urinary flow rate, prostate volume, and serum prostate-specific antigen level were measured. Androgen receptor CAG and GGN genotyping was performed. A CAG repeat length of <21 was associated with an enlarged prostate (hazard ratio (HR) = 1.4, 95% confidence interval (CI): 1.0, 1.9) and a serum prostate-specific antigen level >1.4 ng/ml (HR = 1.5, 95% CI: 1.1, 2.0). A GGN repeat length of <16 was associated with an AUASI >7 (HR = 1.6, 95% CI: 1.1, 2.3) and a serum prostate-specific antigen level >1.4 ng/ml (HR = 1.5, 95% CI: 1.0, 2.3). Having <21 CAG repeats and <16 GGN repeats compared with having neither was associated with an enlarged prostate (HR = 2.5, 95% CI: 1.5, 4.2), a serum prostate-specific antigen level >1.4 ng/ml (HR = 2.8, 95% CI: 1.6, 4.7), a peak flow rate <12 ml/second (HR = 1.9, 95% CI: 1.1, 3.4), and an AUASI >7 (HR = 1.6, 95% CI: 1.0, 2.7). Androgen receptor genepolymorphisms may have a potential role in the pathogenesis of benign prostatic hyperplasia. [ABSTRACT FROM AUTHOR]

The objective was to describe trends in cardiovascular risk factors between 1980–1982 and 1995–1997 in metropolitan Minneapolis-St. Paul, Minnesota. Four population-based surveys of 4,000–6,000 adults aged 25–74 years were conducted in 1980–1982, 1985–1987, 1990–1992, and 1995–1997 using consistent sampling strategies and protocols. The authors completed interviews and examinations to characterize cardiovascular risk factors. Blood samples were drawn and assayed for several analytes including total cholesterol. Although total cholesterol decreased 7–9 mg/dl during the 1980s, no further reduction was noted between 1990–1992 and 1995–1997. Hypercholesterolemia prevalence (total cholesterol of >240 mg/dl and/or use of lipid-lowering medication) fell between 1980–1982 and 1990–1992 but increased thereafter. Current cigarette smoking, systolic blood pressure, and hypertension prevalence decreased significantly between 1980–1982 and 1995–1997. Body mass index increased substantially across the four surveys. Although there was little change in the mean leisure-time physical activity, the proportion of the population not engaging in regular exercise increased between 1990–1992 and 1995–1997. Dietary fat decreased consistently from 1980–1982 to 1995–1997, while overall caloric intake rose 8% in women but not men. To conclude, the favorable trends in hypertension, cigarette smoking, and dietary fat consumption observed in Minneapolis-St. Paul from 1980–1982 to 1995–1997 were paralleled by less favorable recent trends in total cholesterol, hypercholesterolemia, adiposity, and physical activity. [ABSTRACT FROM PUBLISHER]

The authors assessed concordance of local Medicare health care utilization data on cataract surgery and estimates generated using the databases of the Rochester Epidemiology Project, which capture virtually all medical care received by residents of Olmsted County, Minnesota. The Rochester Project databases identified 1, 353 primary cataract extractions performed in Olmsted County between October 1989 and December 1993 among county residents aged ≥65 years. Medicare data identified 1, 148 claims—84.8% of the number of procedures identified by the Rochester Project. Ratios of numbers of encounters (Medicare/Rochester Project) were 189/350 (0.540) for 1992 versus 959/1, 003 (0.956) for the other years combined. Changes in Medicare data file transfer procedures may have produced the 1992 data shortfall. Medicare Compared with source data should periodically be compared with source data to assess concordance. Am J Epidemiol 1997;145:1123-6. [ABSTRACT FROM AUTHOR]

Inflammation may play a role in the development of benign prostatic hyperplasia and/or lower urinary tract symptoms (LUTS). Higher levels of C-reactive protein (CRP) may therefore be associated with the development of these outcomes. The authors examined the association of CRP levels measured in 1996 with rapid increases in prostate volume, prostate-specific antigen levels, and LUTS as well as rapid decreases in peak flow rates (through 2005) in a population-based cohort of men residing in Olmsted County, Minnesota. Men with CRP levels of ≥3.0 mg/L were more likely to have rapid increases in irritative LUTS (odds ratio (OR) = 2.14, 95% confidence interval (CI): 1.18, 3.85) and rapid decreases in peak flow rates (OR = 2.54, 95% CI: 1.09, 5.92) compared with men with CRP levels of <3.0 mg/L. CRP levels were not significantly associated with rapid increases in prostate volume, obstructive LUTS, or prostate-specific antigen levels. Associations were attenuated after adjusting for age, body mass index, hypertension, and smoking history (irritative LUTS: OR = 2.00, 95% CI: 1.04, 3.82; peak flow rate: OR = 2.45, 95% CI: 0.73, 8.25). These results suggest that rapid increases in irritative LUTS and rapid decreases in peak flow rates may be due to inflammatory processes. [ABSTRACT FROM AUTHOR]