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Biomedical subjects

J A Colwell

Publications and source records attributed to J A Colwell.

At least 37 records · Page 2Linked to original sources
PubMed1996

The feasibility of intensive insulin management in non-insulin-dependent diabetes mellitus. Implications of the Veterans Affairs Cooperative Study on Glycemic Control and Complications in NIDDM.

OBJECTIVE: To review the results from the Veterans Affairs Cooperative Study on Glycemic Control and Complications in NIDDM (VACSDM) and to discuss the implications of the results from this feasibility trial. DESIGN: A randomized clinical trial comprising 153 men with non-insulin-dependent diabetes mellitus (NIDDM) who remained hyperglycemic on usual pharmacologic therapy. Patients were randomized into two groups receiving either standard or intensive insulin therapy and were followed for 27 months. SETTING: Five Veterans Affairs medical centers. PATIENTS: 153 men with NIDDM, aged 40 to 69 years, who had hemoglobin A1c (HbA1c) levels of greater than 6.55% while receiving sulfonylurea or insulin therapy. INTERVENTION: Standard insulin therapy was one or two insulin injections daily. Intensive insulin therapy was done using a stepwise approach: 1) evening intermediate or long-acting insulin; 2) addition of daytime glipizide; 3) insulin twice daily, with no glipizide; and 4) insulin three to four times daily, with no glipizide. MEASUREMENTS: Fasting blood glucose and HbA1c levels, retinopathy, lipid and urinary albumin levels, cardiovascular events, hypoglycemia, and body mass index. RESULTS: In the intensive group, the HbA1c level fell 2.07 percentage points; the mean HbA1c level was 7.3% from 6 months onward. The standard group experienced little change. These changes occurred without significant weight gain and with a very low rate of severe hypoglycemia. Sixteen patients (20.5%) in the standard group and 24 patients (32%) in the intensive group had cardiovascular events (P = 0.1). CONCLUSIONS: It is feasible to achieve excellent glycemic control in men with NIDDM in whom standard pharmacologic therapy has failed. The benefit/risk ratio of intensive insulin management in this patient group is not established and has been made the subject of a long-term prospective clinical trial.

Adult↗
PubMed1996

Forum Two: Unanswered research questions about metabolic control in non-insulin-dependent diabetes mellitus.

The participants of Forum Two addressed the unanswered research questions about metabolic control and non-insulin-dependent diabetes mellitus (NIDDM). The most compelling issue was the effect of metabolic control on both the development and progression of macrovascular disease in patients with NIDDM. Associated questions that could be answered by a well-controlled clinical trial related to the goal of blood glucose control in NIDDM in the elderly and in persons with clinical vascular disease. The specific suggestion was a trial similar to the Veterans Affairs Cooperative Study on Glycemic Control and Complications in NIDDM. Another important research issue that was discussed was the benefit of treating other risk factors such as hypertension and hyperlipidemia in diabetic patients. Yet another area discussed was the study of health services delivery to examine the best care-delivery methods for diabetes and other chronic diseases. Other areas of discussion centered on basic research, that is, the fundamental cause of insulin resistance and the genetics of NIDDM and the loss of protection against atherosclerosis in postmenopausal women with diabetes.

Blood Glucose↗
PubMed1996

Intensive insulin therapy in type II diabetes: rationale and collaborative clinical trial results.

The rationale for intensive insulin therapy and results from major clinical trials in diabetes are reviewed. The Diabetes Control and Complications Trial (DCCT) has shown that intensive insulin therapy will prevent or delay the onset of retinopathy, nephropathy, and neuropathy in type I diabetes. The University Group Diabetes Program (UGDP) and the U.K. Prospective Diabetes Study (UKPDS) have addressed the issue of insulin versus oral agent or diet therapy in people with recently diagnosed type II diabetes. The UGDP showed that effective glycemic control could be achieved with intensive insulin therapy, but no effect on vascular end points was seen. Early data from the UKPDS also suggest that intensive insulin therapy may be more effective in lowering HbA1c toward normal than oral agents or diet. A pressing clinical problem is the question of the use of intensive insulin therapy in type II diabetic individuals who remain hyperglycemic despite pharmacological therapy. A Veterans Affairs Cooperative Study explored the feasibility of using intensive insulin therapy in 153 male type II diabetic patients with these characteristics. A 2% lowering of HbA1c was seen, with no increase in weight gain or in hypoglycemia. However, 40 of 153 patients (26.1%) had cardiovascular events during the 27-month trial; no difference in cardiovascular event rates was seen between the two treatment groups. A long-term multicenter collaborative trial is needed to assess the benefit:risk ratio of intensive insulin therapy for type II diabetic patients in whom pharmacological therapy failed to provide glycemic management.

Arteriosclerosis↗
PubMed1995

Veterans Affairs Cooperative Study on glycemic control and complications in type II diabetes (VA CSDM). Results of the feasibility trial. Veterans Affairs Cooperative Study in Type II Diabetes.

OBJECTIVE: It is not clear whether intensive pharmacological therapy can be effectively sustained in non-insulin-dependent diabetes mellitus (NIDDM). The relative risks and benefits of intensive insulin therapy in NIDDM are not well defined. Accordingly, we designed a feasibility study that compared standard therapy and intensive therapy in a group of NIDDM men who required insulin due to sustained hyperglycemia. RESEARCH DESIGN AND METHODS: 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. Patient accrual and adherence, glycohemoglobin (HbA1c), side effects, and measurements of endpoints for a prospective long-term trial were assessed. RESULTS: Accrual goals were met, mean follow-up time was 27 months (range 18-35 months), and patients kept 98.6% of scheduled visits. After 6 months, the mean HbA1c in the intensive therapy group was at or below 7.3% and remained 2% lower than the standard group for the duration of the trial. Most of the decrease in the mean HbA1c in the intensive group was obtained by a single injection of evening intermediate insulin, alone or with daytime glipizide. By the end of the trial, 64% of the patients had advanced to two or more injections of insulin a day, aiming for normal HbA1c. However, only a small additional fall in HbA1c was attained. Severe hypoglycemia was rare (two events per 100 patients per year) and not significantly different between the groups, nor were changes in weight, blood pressure, or plasma lipids. There were 61 new cardiovascular events in 40 patients and 10 deaths (6 due to cardiovascular causes). CONCLUSIONS: Intense stepped insulin therapy in NIDDM patients who have failed glycemic control on pharmacological therapy is effective in maintaining near-normal glycemic control for > 2 years without excessive severe hypoglycemia, weight gain, hypertension, or dyslipidemia. Cardiovascular event rates are high at this stage of NIDDM. A long-term prospective trial is needed to assess the risk-benefit ratio of intensified treatment of hyperglycemia in NIDDM patients requiring insulin.

Aged↗
PubMed1995

Release of platelet plasminogen activator inhibitor 1 in whole blood is increased in patients with type II diabetes.

OBJECTIVE: To compare platelet plasminogen activator inhibitor 1 (PAI-1) release in type II diabetic patients and healthy control subjects. RESEARCH DESIGN AND METHODS: We studied a group of 27 diabetic patients and a group of 16 nondiabetic control subjects. Whole-blood platelet aggregation, defined as a decrease in platelet count during shaking (180 rpm) of blood samples at 37 degrees C, and plasma PAI-1 antigen concentrations were measured in parallel at time 0, 7.5, 15, 30, 60, 120, and 180 min. RESULTS: Platelet aggregation did not differ significantly between the two groups at any time period. However, the increase in plasma PAI-1 antigen concentration over basal levels at time 0 was higher for the group of diabetic patients when compared with their matched control subjects. The increment of PAI-1 antigen was 61.8 +/- 29.4 vs. 35.9 +/- 13.4 ng/ml (P < 0.005, means +/- SD) after 180 min for the diabetic and control subjects, respectively. Platelet PAI-1 release was correlated to very-low-density lipoprotein cholesterol and triglyceride plasma levels, but not to HbA1c levels. CONCLUSIONS: Platelets of patients with type II diabetes release significantly more PAI-1 than platelets of healthy subjects at the same level of platelet aggregation. This may contribute to enhanced thrombosis in diabetes.

Adult↗
PubMed1994

Implants for type II diabetic patients: interim report. VA Implants in Diabetes Study Group.

One hundred seventy-eight implants from three systems were placed in 89 type II diabetic patients at 13 Department of Veterans Affairs medical centers. Four failures (2.2 percent) were found at uncovering. The failure rate increased to 7.3 percent at the end of 1 year (nine additional failures). Study patients will be monitored for an additional 4 years. Initial results suggest that type II diabetic patients can be considered for dental implant therapy.

Dental Care for Chronically Ill↗
PubMed1994

Platelet plasminogen activator inhibitor 1 in patients with type II diabetes.

OBJECTIVE: To compare platelet plasminogen activator inhibitor 1 (PAI-1) concentration in type II diabetic patients and healthy control subjects. RESEARCH DESIGN AND METHODS: We studied a group of 12 diabetic patients whose disease was controlled by diet or sulfonylurea therapy and a group of 17 nondiabetic control subjects. All subjects were free of clinically advanced vascular disease. PAI-1 antigen concentrations were measured in 5 x 10(8) isolated platelets, which were lysed by 1% Triton X-100. RESULTS: Mean platelet PAI-1 was significantly higher in diabetic patients (264 +/- 83 ng/5 x 10(8) platelets) compared with control subjects (202 +/- 71 ng/5 x 10(8) platelets) (P < 0.05). A significant independent positive correlation was found between platelet PAI-1 concentrations and fasting plasma specific insulin levels in the diabetic patients (r = 0.63, P = 0.03). CONCLUSIONS: These findings suggest that 1) a higher platelet PAI-1 concentration may contribute to enhanced thrombosis in type II diabetes and 2) megakaryocyte PAI-1 synthesis may be under the control of insulin.

Blood Platelets↗
PubMed1993

Effects of gemfibrozil on triglyceride levels in patients with NIDDM. Hyperlipidemia in Diabetes Investigators.

OBJECTIVE: Patients with NIDDM have a two- to fourfold increased risk of macrovascular disease. The constellation of elevated TGs and decreased HDL cholesterol are recognized as risk factors and constitute the major dyslipidemia in NIDDM. We therefore sought to determine if gemfibrozil (600 mg b.i.d.) was effective in correcting the dyslipidemia of NIDDM. RESEARCH DESIGN AND METHODS: After 8 wk of placebo stabilization, 442 patients from 46 study centers were randomized to double-blind treatment, in a designated 2:1 ratio, 295 received gemfibrozil and 147 received placebo for 20 wk. The primary end point was plasma TG; secondary end points were TC, LDL cholesterol, VLDL cholesterol, HDL cholesterol, and HbA1c. No baseline differences were noted between groups in sex, age, weight, type of diabetic therapy, fasting plasma levels of TGs, HbA1c, or C-peptide. About two-thirds received oral hypoglycemic drugs, one-third insulin. RESULTS: TG fell 26.4% in the gemfibrozil group and rose 7.4% in the placebo group (P < 0.023), by an intent-to-treat analysis. When patients who were noncompliant or with inadequate data were excluded, similar results were found--a 30.4% fall with gemfibrozil and a 4.8% increase with placebo (P < 0.0001). TG levels fell within 4 wk and remained low for 20 wk (P < 0.001). Mean HDL cholesterol rose by 4 wk and increased further at 12 wk (8-12%), P < 0.0001. TC fell. We observed a significant rise in LDL cholesterol in both gemfibrozil- and placebo-treated groups, with no significant differences between these groups. Changes in HbA1c were similar in gemfibrozil and placebo groups. No differences were observed in responses in groups treated with insulin and or oral hypoglycemic drugs. Overall AEs that were clinically important occurred in 6.1% in the gemfibrozil group vs. 2.0% in the placebo group (NS). CONCLUSIONS: We conclude that gemfibrozil is an effective and safe agent in combating the dyslipidemia of NIDDM, irrespective of type of diabetic therapy.

C-Peptide↗
PubMed1991

Pathophysiology of vascular disease in diabetes: effects of gliclazide.

Diabetes mellitus is a major risk factor for coronary heart disease, peripheral vascular disease, and cardiovascular disease. The prevalence of these complications is increased about two- to four-fold in people with diabetes in the United States, and they contribute substantially to morbidity, mortality, and healthcare costs. The pathogenesis of macrovascular disease in diabetes is multifactorial. Endothelial injury is an early event, followed by macrophage adherence and uptake of lipids to produce a fatty streak. Platelet adherence, aggregation, and release of thromboxane and platelet-derived growth factors may then occur. Quantitative and qualitative alterations of lipoproteins are seen, particularly in uncontrolled insulin-dependent and non-insulin-dependent diabetes. Hyperinsulinemia may be contributory, as may elevated plasma proinsulin levels. Glycation of plasma proteins and of components of the vascular wall occurs, and altered coagulation and/or fibrinolysis may lead to thrombosis. The process is accelerated by hypertension, smoking, and hypercholesterolemia. Gliclazide is an oral sulfonylurea agent that has been reported to have actions on platelet function and fibrinolysis in addition to its effects on glycemia. The evidence for this is reviewed, and recommendations for future studies are made.

Arteriosclerosis↗