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OBJECTIVE: To determine if there is any association between glycemia and blood pressure in black patients with hypertension and diabetes mellitus whose antihypertensive medications had been unchanged for six months. DESIGN: Retrospective, from March 1990 through February 1991. SETTING: Internal medicine ambulatory clinic at Detroit Receiving Hospital/University Health Center. PATIENTS: Patients seen during this period with hypertension and type II diabetes. Of the 639 possible subjects, 124 met the following criteria: (1) no change in antihypertensive medications for six months, (2) absence of secondary hypertension, and (3) weight change (if any) was less than five percent. Changes in antihypertensive medication(s) excluded 388 patients, secondary hypertension excluded 3, weight changes of more than five percent excluded 94, and lack of matching postprandial capillary blood glucose (PCBG) values excluded 30. The mean age of the subjects was 66.8 years, mean diabetes duration was 12.0 years, mean PCBG was 10.7 mmol, mean systolic blood pressure (SBP) was 154.3 mm Hg, mean diastolic blood pressure (DBP) was 90.1 mm Hg. There were 28 men in the study and 96 women; 90 were obese (body mass index >25 kg/m2) and 34 were nonobese. The diabetes was managed with insulin in 67 patients, with sulfonylureas in 50, and with diet in 7. intervention: None MAIN OUTCOME MEASURES: SBP and DBP versus PCBG at matching times both at baseline and at six months. RESULTS: There was a positive association between blood pressure measurements and glycemia. Overall change in SBP was strongly correlated with PCBG changes (r=0.745, pCONCLUSIONS: Glycemia is positively associated with blood pressure.

A gastrointestinal bleeding study was performed on 2 occasions on a 91-year-old woman. The in vitro method of red blood cell labeling with Tc-99m was used. Both studies were negative. The first study showed normal activity in the heart, liver, and great vessels. The second study was performed using cells from donor packed cells infused the day of the study. Using the heart as the reference organ, the relative degree of liver uptake is normally 50% with labeled autologous blood. The authors found a relative degree of liver uptake greater than 90% using labeled transfused red blood cells.

OBJECTIVE: To review the comparative efficacy of metformin, sulfonylureas, and insulin in the treatment of patients with type II diabetes. DATA SOURCES: Articles were identified by a MEDLINE search of articles from 1966 to 1994, using the terms metformin, sulfonylurea, chlorpropamide, glipizide, glyburide, tolazamide, tolbutamide, and insulin, published in English, French, or German. Articles also were identified from bibliographies of pertinent articles. STUDY SELECTION: With the exception of articles dealing with the pharmacology of metformin, only randomized, active, controlled studies were selected for review. DATA EXTRACTION: Effects of metformin therapy on metabolic and cardiovascular risk factors were abstracted: weight, blood pressure, total and low-density lipoprotein cholesterol, triglycerides, fasting and postprandial glucose, and glycosylated hemoglobin. DATA SYNTHESIS: Metformin is an antihyperglycemic agent with a mean bioavailability of 50–60%. It is eliminated primarily by renal filtration and secretion and has a half-life of approximately 6 hours in patients with type II diabetes. Although the half-life of metformin is prolonged in patients with renal impairment, no specific dosage adjustments have been recommended. This agent has no effect in the absence of insulin. Metformin is as effective as the sulfonylureas in treating patients with type II diabetes and has a more prominent postprandial effect than the sulfonylureas or insulin. When combined with a sulfonylurea, metformin has been shown to exert antihyperglycemic effects in addition to the sulfonylurea with which it is combined. Metformin decreases absorption of vitamin B12 and folic acid, although reported cases of megaloblastic anemia are rare. Cimetidine decreases the elimination of metformin; therefore, the manufacturer reccommends a reduced metformin dosage when these agents are combined. The most frequently reported adverse effects of metformin are gastrointestinal in nature (diarrhea, nausea, abdominal pain, and metallic taste, in decreasing order). Metformin has been used in Canada, Great Britain, and the rest of Europe for more than 30 years and was approved for use in the US in December 1994. CONCLUSIONS: Three trials comprise the Food and Drug Administration approval database (one foreign). Metformin will be most useful in managing patients with poorly controlled postprandial hyperglycemia, as its postprandial effect is much greater than that of the sulfonylureas. In contrast, sulfonylureas or insulin are more effective for managing patients with poorly controlled fasting hyperglycemia. Metformin should be considered a first-line agent, particularly in obese or hyperlipidemic patients. Wayne R Melchior PharmD BCPS, Drug Information Specialist, St Joseph Mercy Hospital, Pontiac, MI; and Adjunct Professor, Drug Information, Department of Pharmacy Practice, Ferris State University, Big Rapids, MI Linda A Jaber PharmD, Assistant Professor, Department of Pharmacy Practice, College of Pharmacy, Wayne State University, 328 Shapero Hall, 1400 Chrysler Dr, Detroit, MI 48201, FAX 313/577-5369

OBJECTIVE: Diabetic nephropathy (DN) is a leading cause of kidney disease in the US. At least four factors influence whether people with diabetes will develop DN: (1) hypertension, (2) hyperglycemia, (3) dietary protein intake, and (4) intrarenal hemodynamics. The angiotensin-converting enzyme (ACE) inhibitors are known to affect blood pressure (BP) and intrarenal hemodynamics; thus, they may prevent the onset of DN or slow the decline in renal function once DN has been diagnosed. DATA SOURCES: English-language, controlled, and crossover studies published between 1973 and 1991 and indexed in MEDLINE under the headings diabetic nephropathies and angiotensin-converting enzyme inhibitors. MAIN OUTCOME MEASURES: The primary outcome indicators of interest were the effects of the ACE inhibitors captopril, enalapril, and lisinopril on BP control and urinary albumin excretion rate. CONCLUSIONS: ACE inhibitors delay the onset and slow the progression of DN in people with diabetes independent of BP effects. They also slow the progression of DN in people with diabetes who have poorly controlled hyperglycemia. The proper dose and time at which to initiate ACE inhibitor therapy to prevent the appearance of DN is not known. It is also not known how long the beneficial effects of ACE-inhibitor therapy persists as only two studies have followed patients for more than one year. Finally, large, long-term, controlled clinical trials are needed before ACE inhibitors can be considered for prophylactic use to prevent the onset and/or progression of DN.

beta-Adrenergic blockers are less efficacious as monotherapy for the treatment of hypertension in blacks as compared with whites. Because beta-adrenergic stimulation and blockade differ between racial groups, biochemical differences in the beta-adrenergic pathway may exist. It is the intent of this report to show underlying similarities and differences, at least in part, in the beta-adrenergic pathway (e.g., baseline cAMP and protein concentrations) using the T-lymphocyte as the model system. A total of 20 (n = 10 black, n = 10 white) normotensive male volunteers were recruited, begun on a low-sodium diet to normalize serum catecholamines, and blood was collected for lymphocyte beta-receptor isotherm binding experiments and cAMP determination. There were no differences in Bmax, sites per cell, or kd. Basal cAMP concentrations were significantly higher in the black group (16.0 +/- 9.8 pmol/10(6) cells) compared with the white group (7.0 +/- 1.8 pmol/10(6) cells) (p less than 0.05). Protein levels from the lymphocyte suspension were also higher in the black group (1,081.0 +/- 367.7 micrograms/ml) compared with the white group (766.8 +/- 220.4 micrograms/ml) (p less than 0.05). Normalization of cAMP for protein yielded 83.2 +/- 55.4 fmol/micrograms protein in the black group and 56.6 +/- 29.8 fmol/micrograms protein in the white group (p = 0.11). Altered protein levels may be a confounding variable in studies of this type. Further work is necessary to identify the nature and significance of this protein elevation, its relationship to the adenylate cyclase system in lymphocytes, and the source of the cAMP elevation noted herein.