Type II Diabetes and Syndrome X: Pathogenesis and Glycemic Management

Socioeconomic status in association with metabolic syndrome and coronary heart disease risk

Background

The purpose of this study was to examine the association of metabolic syndrome (MS) coronary heart disease (CHD) with socioeconomic status (SES).

Methods

The participants were 2,170 (631 men and 1,539 women), aged over 40 years who had visited for health screening from April to December in 2009. We classified them into three SES levels according to their education and income levels. MS was defined using the criteria of modified National Cholesterol Education Program Adult Treatment Panel III and CHD risk was defined using Framingham risk score (FRS) ≥ 10%.

Results

High, middle, and low SES were 12.0%, 73.7%, and 14.3%, respectively. The prevalence of MS was 18.1%. For high, middle, and low SES, after adjusted covariates (age, drinking, smoking, and exercise), odds ratios for MS in men were 1.0, 1.41 (confidence interval [CI], 0.83 to 2.38; P > 0.05), and 1.50 (CI, 0.69 to 3.27; P > 0.05), respectively and in women were 1.0, 1.74 (CI, 1.05 to 3.18; P < 0.05), and 2.81 (CI, 1.46 to 2.43; P < 0.05), respectively. The prevalence of FRS ≥ 10% was 33.5% (adjusted covariates were drinking, smoking, and exercise) and odds ratios for FRS ≥ 10% in men were 1.0, 2.86 (CI, 1.35 to 6.08; P < 0.001), and 3.12 (CI, 1.94 to 5.00; P < 0.001), respectively and in women were 1.0, 3.24 (CI, 1.71 to 6.12; P < 0.001), and 8.80 (CI, 4.50 to 17.23; P < 0.001), respectively.

Conclusion

There was an inverse relationship between SES and FRS ≥ 10% risk in men, and an inverse relationship between SES and both risk of MS and FRS ≥ 10% in women.

{beta}-Cell mass dynamics and islet cell plasticity in human type 2 diabetes

Studies of long-standing type 2 diabetes (T2D) report a deficit in beta-cell mass due to increased apoptosis, whereas neogenesis and replication are unaffected. It is unclear whether these changes are a cause or a consequence of T2D. Moreover, whereas islet morphogenetic plasticity has been demonstrated in vitro, the in situ plasticity of islets, as well as the effect of T2D on endocrine differentiation, is unknown. We compared beta-cell volume, neogenesis, replication, and apoptosis in pancreata from lean and obese (body mass index > or = 27 kg/m(2)) diabetic (5 +/- 2 yr since diagnosis) and nondiabetic cadaveric donors. We also subjected isolated islets from diabetic (3 +/- 1 yr since diagnosis) and nondiabetic donors to an established in vitro model of islet plasticity. Differences in beta-cell volume between diabetic and nondiabetic donors were consistently less pronounced than those reported in long-standing T2D. A compensatory increase in beta-cell neogenesis appeared to mediate this effect. Studies of induced plasticity indicated that islets from diabetic donors were capable of epithelial dedifferentiation but did not demonstrate regenerative potential, as was seen in islets from nondiabetic donors. This deficiency was associated with the overexpression of Notch signaling molecules and a decreased neurogenin-3(+) cell frequency. One interpretation of these results would be that decreased beta-cell volume is a consequence, not a cause, of T2D, mediated by increased apoptosis and attenuated beta-cell (re)generation. However, other explanations are also possible. It remains to be seen whether the morphogenetic plasticity of human islets, deficient in vitro in islets from diabetic donors, is a component of normal beta-cell mass dynamics.

Care of the cancer survivor: metabolic syndrome after hormone-modifying therapy

Emerging evidence implicates metabolic syndrome as a long-term cancer risk factor but also suggests that certain cancer therapies might increase patients' risk of developing metabolic syndrome secondary to cancer therapy. In particular, breast cancer and prostate cancer are driven in part by sex hormones; thus, treatment for both diseases is often based on hormone-modifying therapy. Androgen suppression therapy in men with prostate cancer is associated with dyslipidemia, increasing risk of cardiovascular disease, and insulin resistance. Anti-estrogen therapy in women with breast cancer can affect lipid profiles, cardiovascular risk, and liver function. As the number of cancer survivors continues to grow, treating physicians must be aware of the potential risks facing patients who have been treated with either androgen suppression therapy or anti-estrogen therapy so that early diagnosis and intervention can be achieved.

Metformin: mechanisms of antihyperglycemic action, other pharmacodynamic properties, and safety perspectives

OBJECTIVE

To characterize the mechanisms of action of metformin and describe its effects and safety profile.

METHODS

Results of more than 30 years of clinical use in countries other than the United States are summarized. In addition, the pharmacologic properties of metformin are compared with those of other antihyperglycemic agents.

RESULTS

Approximately 90% of all cases of diabetes are non-insulin-dependent diabetes mellitus (NIDDM)--a heterogeneous disease that involves several pathogenic factors and is associated with other coexisting conditions, such as cardiovascular disease, hypertension, and obesity. Thus, an agent that controls blood glucose levels and has favorable effects on the concomitant conditions should be considered when pharmacologic intervention is needed for the treatment of NIDDM. Metformin possesses the pharmacodynamic properties to do both. Its mechanisms of action include the reduction of hepatic glucose production and enhancement of peripheral glucose disposal, making metformin an effective antihyperglycemic agent. It also has other pharmacologic properties, independent of its glycemic effects, that offer additional clinical benefits in comparison with other pharmacologic NIDDM treatments. These benefits include stabilization or even loss of weight in patients for whom weight gain is a concern and reduction of plasma lipid levels in patients with hyperlipidemia.

CONCLUSION

On the basis of 3 decades of clinical experience, metformin has been shown to be not only a well tolerated but also a highly effective antihyperglycemic agent.

Insulin resistance syndrome and type 2 diabetes mellitus

Patients with type 2 diabetes mellitus have an elevated risk of morbidity and mortality from cardiovascular disease. This risk is partly attributable to an increased prevalence of classic coronary artery disease risk factors and partly because of hyperglycemia itself and a highly atherogenic lipid profile. The altered composition of lipoproteins and lipids in type 2 diabetic patients, termed diabetic dyslipidemia, is characterized by: (1) elevated levels of triglyceride; (2) normal levels of total and low-density lipoprotein cholesterol (LDL-C); (3) reduced levels of high-density lipoprotein cholesterol (HDL-C); (4) elevated levels of apolipoprotein B; (5) a preponderance of small, dense LDL particles; and (6) increased levels of cholesterol-rich very-low-density lipoprotein. In most cases, diabetic dyslipidemia is preceded by hyperinsulinemia resulting from insulin resistance. Because patients with type 2 diabetes and insulin resistance are at a markedly increased risk of atherosclerosis, and because strict control of glycemia has proved beneficial in reducing microangiopathy but not macroangiopathy, treatment of diabetic dyslipidemia should be aggressive. Target levels have, therefore, been set at <2.6 mmol/L (100 mg/dL) for LDL-C, <2.3 mmol/L [200 mg/dL] for triglycerides, and >1.15 mmol/L (45 mg/dL) for HDL-C. Trial data suggest that these target levels are likely to be achieved with statins, if necessary, in combination with fibrates or nicotinic acid derivatives. Furthermore, in large-scale clinical trials (eg, Scandinavian Simvastatin Survival Study [4S] and the Cholesterol and Recurrent Events [CARE] study), it has been demonstrated that lipid lowering can appreciably reduce cardiovascular events in diabetic patients.

Influence of moderate chronic wine consumption on insulin sensitivity and other correlates of syndrome X in moderately obese women

Epidemiologic studies indicate that alcohol consumption is associated with improved insulin sensitivity; however, scant experimental evidence confirms this observation. To determine the effects of regular moderate wine consumption on insulin sensitivity, 20 overweight women (body mass index [BMI], 29.8 +/- 2.2 kg/m2) participated in a 20-week free-living randomized crossover trial. The subjects, serving as their own controls, consumed wine (190 mL red wine, 13% vol/vol ethanol, 5 days per week) for 10 weeks and abstained for 10 weeks or vice versa. The dependent variables (body weight, BMI, percent body fat, blood pressure, fasting blood glucose and insulin, blood lipids, dietary intake, and insulin sensitivity by intravenous glucose tolerance test [IVGTT]) were measured at the pretest, at the 10-week crossover, and at the 20-week completion of the study. Data were analyzed at the pretest and at completion of the wine drinking and abstention periods of the study using ANOVA by order of treatment. Fasting glucose remained unchanged (mean +/- SD; P > .05) throughout the experiment (pretest, drinking, and abstention, 91.1 +/- 9.2, 91.6 +/- 9.1, and 88.5 +/- 11.2 mg/dL), as did the measures of insulin sensitivity, fasting insulin (pretest, drinking, and abstention, 8.6 +/- 3.3, 8.6 +/- 4.1, and 9.1 +/- 4.7 microU/mg) and the insulin sensitivity index (3.60 +/- 2.96, 3.25 +/- 2.17, and 3.30 +/- 1.84). Body composition and blood lipids also remained unchanged (P > .05) during treatment. Moderate wine consumption at this dose in overweight women did not improve or impair insulin sensitivity, nor did it change any of the known correlates of insulin sensitivity, including body weight and composition, blood lipids, and blood pressure.

Metformin: effects on cardiovascular risk factors in patients with non-insulin-dependent diabetes mellitus

Non-insulin-dependent diabetes mellitus (NIDDM) affects approximately 12 million people in the United States. NIDDM is frequently found to coexist with other conditions, such as obesity, dyslipidemia, atherosclerotic vascular disease, and hypertension, which contribute to morbidity and mortality. Although the major clinical objective in the management of NIDDM is to control hyperglycemia, the long-term objective is to prevent microvascular and macrovascular complications. Cardiovascular disease is the major cause of death in NIDDM patients. Although hyperglycemia may be adequately controlled, risk factors for coronary heart disease may remain unchanged. Treatment with metformin controls hyperglycemia and may have positive effects on cardiovascular risk factors. When used alone or in combination with sulfonylureas, metformin tends to stabilize or decrease weight, maintains or reduces insulin levels, has beneficial effects on plasma lipid profiles, and may also have beneficial effects on blood pressure and the fibrinolytic system.

Type A behavior and metabolic syndrome precursors in young adults

The association between type A behavior and a cluster of parameters of the metabolic syndrome was studied in 919 randomly selected healthy young adults. Type A behavior was measured using the Type A Behavior Questionnaire for the Finnish Multicenter Study and the Hunter Wolf A-B Rating Scale. The results showed that type A men scored higher on the "Metabolic Syndrome Precursors Factor," representing a metabolic entity, than did non-type A men. In addition, type A behavior had a moderating effect on the relationship between parameters of the metabolic syndrome, that is, interdependence of these somatic factors was stronger in type A men than in non-type A men. These findings were not true of women. It is discussed whether type A behavior might affect bodily functions through increased activity along the pituitary-adrenal system resulting in insulin resistance, compensatory hyperinsulinemia, and other characteristics of the metabolic syndrome.