Prevention of diabetes-induced cardiovascular complications upon treatment with antioxidants.

Oxidative stress is considered to play an important role in the pathogenesis of diabetes-induced cardiovascular disease (CVD), which is invariably associated with abnormal blood lipid profile, insulin resistance and metabolic syndrome. Stress, smoking, high saturated fat intake as well as low fruit and vegetable intakes have been shown to increase oxidative stress and hyperlipidemia, which increase the predisposition of diabetic subjects to atherosclerosis, stroke and coronary heart disease. The oxidation of low-density lipoprotein by oxidative stress is essential for the development of atherosclerosis, and the reduction in oxidative stress as well as blood glucose and cholesterol is considered critical for the prevention of diabetes-induced CVD. Although epidemiological studies have demonstrated that vitamin C and vitamin E decrease the incidence of coronary heart disease, different clinical trials have failed to support the beneficial effect of these antioxidants. Nonetheless, it has been suggested that natural forms of these vitamins may be more efficacious than synthetic vitamins, and this may explain the inconsistencies in results. Antioxidants, N-acetyl-L-cysteine and resveratrol, have also been shown to attenuate the diabetes-induced cardiovascular complications. It has been indicated that the antioxidant therapy may be effective in a prevention strategy rather than as a treatment for CVD. The evidence presented here supports the view that cardiovascular complications in diabetes may be induced by oxidative stress and appropriate antioxidant therapy may be promising for attenuating the progression of diabetes-induced CVD.

Prevalence of obesity, physical inactivity and undernutrition, a triple burden of diseases during transition in a developing economy. The Five City Study Group.

OBJECTIVE AND DESIGN: The objective of the study was to find out the prevalence of overweight, obesity, undernutrition and physical activity status in the urban populations of India. Cross-sectional surveys were conducted in 6-12 urban streets in each of five cities in five different regions of India using a common study protocol and criteria of diagnosis. SUBJECTS AND METHODS: A total of 6940 subjects (3433 women and 3507 men) aged 25 years and above were randomly selected from the cities of Moradabad (n = 2002),Trivandrum (n = 1602), Calcutta (n = 900), Nagpur (n = 894) and Bombay (n = 1542). Evaluation and validation were performed by a physician and dietitian-administered questionnaire at Moradabad. After pooling of data, all subjects were divided into various age groups for men and women. Obesity (body mass index = 30 > kg/m(2)) and overweight (BMI 2 25-29.9 kg/m(2) and > 23 kg/m(2)) as well as waist-hip ratio (> 0.85 in women and > 0.88 in men, central obesity) were calculated and physical activity status assessed by a validated questionnaire. RESULTS: The overall prevalence of obesity was 6.8% (7.8 vs. 6.2%, P < 0.05) and overweight 33.5% (35.0 vs. 32.0%, P < 0.05) among women and men, respectively. The highest prevalence of obesity (7.8%) and overweight (36.9%) was found among subjects aged 35 to 44 years in both sexes. The prevalence of obesity was significantly (P < 0.05) greater in Trivandrum (8.5%), Calcutta (7. 1%) and Bombay (8.3%) compared to Moradabad (6.2%) among women and in Trivandrum (7.4%) and Bombay (7.2%), compared to Nagpur (5.0%) among men. There was a significant decreasing trend in obesity (P < 0.05) and overweight (P < 0.05) with increasing age above 35-44 years in both sexes. The overall prevalence of subjects > 23 kg/m(2) was 50.8% and central obesity 52.6%. The overall prevalence of sedentary behaviour was 59.3% among women and 58.5% among men. Both sedentary behaviour and mild activity showed a significant increasing trend in women after the age of 35-44 years. In men, such a trend was observed above the age of 45 years. Sedentary behaviour was significantly (P < 0.05) greater in Trivandrum, Calcutta, and Bombay compared to Nagpur. Sedentary behaviour was significantly (P < 0.001) associated with obesity in both sexes, compared to non-obese men and women. The overall prevalence of undernutrition was 5.5% (n = 380) which was significantly more common in Moradabad, north and Nagpur, central India compared to other cities. CONCLUSIONS: Obesity, overweight and central obesity and sedentary behaviour coexist with undernutrition, and have become a public health problem in all the five cities of India. The prevalence of obesity and sedentary behaviour was significantly greater in Trivandrum, Calcutta and Bombay compared to Moradabad and Nagpur. Sedentary behaviour was significantly associated with obesity compared to non-obese subjects in both sexes, which may be due to greater economic development in metro cities.

Mechanisms of acute myocardial infarction study (MAMIS).

Acute myocardial infarction (AMI) is a highly dynamic event, which is associated with marked neuroendocrinological dysfunction in addition to cardiac damage. The immediate trigger for AMI is not precisely known. Studies conducted by Lown, Braunwald, Halberg, Otsuka and our group have demonstrated a marked increase in sympathetic activity, oxidative stress, and magnesium and potassium deficiency during AMI. Clinical studies have reported an increased incidence of AMI, sudden death and ischemia during first quarter of the day when there is a rapid withdrawal of vagal activity and increase in sympathetic tone. In one case-control study of 202 patients with AMI, there was a significant (P < 0.02) increase in cardiac events in the second quarter of the day compared to other quarters, respectively (16.8%, 41.0%, 13.8%, 28.2% per quarter). This characteristic remained prevalent in both men and women and among patients with and without known AMI (n = 52), diabetes (n = 53) or hypertension (n = 75). Triggers of AMI were noted among 162 (82.2%) of the patients. Neuropsychological mechanisms were observed as follows: emotional stress (45.5%), sleep deprivation (27.7%), cold climate (29.2%), hot climate (24.7%), large meals (47.5%) and physical exertion (31.2%). These triggering factors are known to enhance sympathetic activity and decrease vagal tone, resulting in an increased secretion of plasma cortisol, noradrenaline, aldosterone, angiotension-converting enzyme (ACE), interleukin (IL)-1, -2, -6, -18, and tumor necrosis factor-alpha (TNF-alpha), all of which are are proinflammatory agents. There is also a deficiency in the serum levels of vitamin A, E, and C and magnesium, potassium, melatonin, and IL-10 (an anti-inflammatory agent). In our study, we found a decrease in magnesium, potassium, vitamin A, E, C and beta carotene combined with an increase in thiobarbituric acid-reactive substances (TBARS), MDA and diene conjugates, TNF-alpha and IL-6, all of which are indicators of oxidative damage and proinflammatory activity, respectively.