Role of environmental factors in the development of noninsulin-dependent diabetes mellitus

Design and synthesis of rosiglitazone-ferulic acid-nitric oxide donor trihybrids for improving glucose tolerance

Glucose intolerance is associated with metabolic syndrome and type 2 diabetes mellitus (T2DM) while some new therapeutic drugs, such as rosiglitazone (Rosi), for T2DM can cause severe cardiovascular side effects. Herein we report the synthesis of Rosi-ferulic acid (FA)-nitric oxide (NO) donor trihybrids to improve glucose tolerance and minimize the side effects. In comparison with Rosi, the most active compound 21 exhibited better effects on improving glucose tolerance, which was associated with its NO production, antioxidant and anti-inflammatory activities. Furthermore, 21 displayed relatively high stability in the simulated gastrointestinal environments and human liver microsomes, and released Rosi in plasma. More importantly, 21, unlike Rosi, had little stimulatory effect on the membrane translocation of aquaporin-2 (AQP2) in kidney collecting duct epithelial cells. These, together with a better safety profile, suggest that the trihybrids, like 21, may be promising candidates for intervention of glucose intolerance-related metabolic syndrome and T2DM.

CYP105A1 mediated 3-hydroxylation of glimepiride and glibenclamide using a recombinant Bacillus megaterium whole-cell catalyst

CYP105A1 from Streptomyces griseolus belongs to a widespread family of soluble prokaryotic cytochromes P450. For in vitro studies we established an electron transfer system, consisting of the ferredoxin Etp1(fd) and the ferredoxin reductase Arh1 from the fission yeast Schizosaccharomyces pombe. We investigated the metabolism of glibenclamide and glimepiride, hypoglycemic drugs of sulfonylurea type, and determined corresponding in vitro kinetic parameters. The resulting 3-cyclohexyl-hydroxylation activity towards glibenclamide and glimepiride was demonstrated by NMR analysis. Furthermore, the main product of glibenclamide, cis-3-hydroxy-glibenclamide is identical with the phase-1-metabolite of this drug in human. The orientation of glimepiride and glibenclamide in the active site of the enzyme is shown by a computational docking model. For high scale production of sulfonylurea derivatives, we designed whole-cell biocatalysts based on Bacillus megaterium MS941. Surprisingly, the system expressing only CYP105A1 showed a similar activity towards hydroxylation of glimepiride and glibenclamide compared to the system expressing additionally the redox partners, Arh1 and Etp1(fd)(516-618), indicating that the host strain provides a functional endogenous electron transfer system.

The relationship of blood pressure to blood glucose and physical leisure time activity. A study of hypertension in a survey of middle-aged subjects in Uppsala 1981-82

Hypertension was detected in 56 of 436 women and 34 of 371 men in an urban population sample of 47-54-year-old individuals. The prevalence of glucose intolerance according to WHO criteria was 22.2% in the hypertensive group and 4.3% among the normotensives, with mean 2-hour blood glucose values of 5.8 and 4.4 mmol X 1(-1), respectively. The difference in mean 2-hour blood glucose was independent of body mass index, physical activity during leisure time or at work, age and smoking in covariance analysis. Subjects with high physical leisure time activity (n = 125) had a lower mean blood pressure and a lower prevalence of hypertension, 4.8%, than those with low activity (n = 682), 12.3%. The increase in diastolic blood pressure in the latter group and the male subgroup appeared to be independent of body mass index, physical job activity, age and smoking. Multiple regression analyses with blood pressure as dependent variable and six metabolic and clinical characteristics as predictors identified 2-hour blood glucose and body mass index as the most important predictors. Physical leisure time activity was associated with diastolic blood pressure, however only when 2-hour blood glucose was not included as predictor. Thus, physical activity may exert an influence on the blood pressure level mainly through changes in glucose tolerance and/or body weight, although alternative mechanisms cannot be excluded.

Pattern of non-insulin dependent diabetes mellitus in Kuwait

The aim of this study was to examine distinctive clinical characteristics of non-insulin dependent diabetes mellitus (NIDDM) patients in Kuwait including mode of presentation at diagnosis, family history of diabetes, therapeutic management and response to treatment. We studied 3299 Kuwaiti patients (1454 male (M) and 1845 female (F) subjects) registered in Salmiya diabetic clinic, a part of the national network of diabetes control and care programme, and located in the urban Hawally Governorate, Kuwait. The mean age of the patients was 53 years (+/- 13.9 years), and 73.8% were in the age group 45-64 years. The majority of patients (53.6%) were diagnosed as they were clinically symptomatic; in contrast a significant minority (37.8%) were diagnosed by chance mainly during investigation for unrelated events. The 8.6% of the women diagnosed during pregnancy had a high parity index 6.5 +/- 2.9. A high percentage of the diabetic patients (63%) reported a positive family history in first degree relatives. The mean duration of diabetes mellitus was 7.8 years (range 2-28 years) and 70% of the patients had diabetes mellitus for 9 years or less. The mean body mass index (BMI) was 31.8 +/- 6.3 kg/m2 and 28.5 +/- 6.3 kg/m2 in women and men, respectively. Among the diabetic women 57.7% were obese (BM > 30 kg/m2) and 30.2% were overweight (BMI 25-30 kg/m2) as compared to 33.6% and 44.3% among diabetic men, respectively. High blood pressure (> or = 160/95 mmHg) was reported in 14.9%. The main therapeutic modality in the majority of patients, (63.2%), was the administration of oral hypoglycaemic agents (OHA), while 23.7% were on a diet regimen and only 13.1% were on insulin therapy. The study throws light on the pattern of NIDDM among Kuwaiti patients. Frequent association with obesity suggests that it may be a major risk factor. The strong familial aggregation reported paves the way for future research among these families for cosegregation of a defined genetic trait with NIDDM in the Arab population subset.

Incidence and predictors of diabetes in Japanese-American men. The Honolulu Heart Program

Reports on the incidence and predictors of diabetes in minority populations are infrequent. The 6-year cumulative incidence of diabetes between 1965 and 1974 was estimated among 7210 Japanese-American men aged 45 to 68 years who were enrolled in the Honolulu Heart Program and were free of clinically recognized diabetes at baseline. The incidence of "possible" diabetes (based on history, medication, or hospital diagnosis) was 12.8% and the incidence of "probable" diabetes (based on diabetic medication) was 5.7%. Estimates of incidence in subjects with a nonfasting glucose concentration less than 225 mg/dL 1 hour after a 50-g load were 9.7 and 4.0%, respectively. Multivariate adjusted odds ratios (ORs) for probable diabetes in all subjects comparing the upper quintile with the lower four quintiles combined for continuous variables indicated statistically significant direct associations with body mass index (OR, 1.69; 95% confidence interval (CI), 1.31 to 2.18), 1-hour postchallenge glucose level (OR, 5.79; 95% CI, 4.58 to 7.33), triglyceride levels (OR, 1.47; 95% CI, 1.14 to 1.91), systolic blood pressure (OR, 1.36; 95% CI, 1.05 to 1.76), and parental history of diabetes (OR, 1.73; 95% CI, 1.29 to 2.33), and an inverse association with physical activity (OR, 0.49; 95% CI, 0.34 to 0.72), using logistic regression models including these variables as well as age, subscapular/triceps skinfold ratio, and hematocrit simultaneously. Associations were similar but slightly weaker in men with glucose levels less than 225 mg/dL and in those who remained free of cardiovascular disease. When older men (55 to 68 years old) were compared with younger (45 to 54 years old) men, associations among the older group were stronger for body mass index, physical activity, and systolic blood pressure and they were weaker for glucose levels, triglyceride values, and parental diabetes. Results suggest that body mass index, physical inactivity, glucose level, and parental diabetes appear to be independent risk factors for diabetes, while triglyceride and systolic blood pressure levels may be markers for an adverse cardiovascular risk factor profile associated with diabetes and may reflect an insulin resistance syndrome.

Non-insulin-dependent diabetes mellitus: diagnostic and therapeutic challenges in the severely burned patient--a case report

The purpose of this paper is to describe the management of a previously undiagnosed non-insulin-dependent diabetic patient with a severe burn injury. The hyperglycaemia and glucose intolerance following burn injury was complicated by the hyperglycaemia of diabetes mellitus. Intravenous insulin infusion monitored by hourly glucose levels was required to manage this hyperglycaemia. During day 11 postburn injury, this patient required 2104 units of insulin to control his hyperglycaemia. Aggressive detection and management of infections complemented by early debridement and coverage of the burn wound were other important considerations in the management of this patient. The diagnosis of non-insulin-dependent diabetes mellitus (NIDDM) was made after the patient recovered from his burn injury. His rehabilitation programme has included primary prevention strategies for NIDDM that focus on health-improving behaviours such as improved diet, exercise, and weight control.

Treatment of non-insulin-dependent diabetes mellitus and its complications. A state of the art review

Non-insulin-dependent diabetes mellitus (NIDDM) is a major health problem which occurs predominantly in the older population; 16.8% of persons over age 65 years have NIDDM. The total health costs of NIDDM are in excess of $US20 billion annually. The primary objective in the treatment of NIDDM is to achieve normoglycaemia, without aggravating coexisting abnormalities. Common abnormalities include obesity, hypertension, retinopathy, nephropathy and neuropathies. Diet, and consequent bodyweight reduction, is the cornerstone of therapy for NIDDM. Total calorie intake should be limited, while the percentage of calories from carbohydrates should be increased and that from fats and cholesterol should be decreased. Exercise may also help to reduce bodyweight. Sulphonylurea drugs stimulate insulin secretion from beta-cells, and may be a useful adjunct to nonpharmacological therapy. Failure to respond to sulphonylurea drugs may be primary (25 to 30% of initially treated patients) or secondary (5 to 10% per year). It is not clear which is the most effective pharmacological intervention in such cases. Options include switching to or combining therapy with insulin, a biguanide, or other insulin-sparing antihyperglycaemic agents, e.g. alpha-glucosidase inhibitors, thiazolidinediones, chloroquine or hydroxychloroquine, or fibric acid derivatives such as clofibrate. Other experimental agents include the fatty acid oxidation inhibitors and dichloroacetate. Specific agents, such as antihypertensives, lipid lowering agents and sorbitol inhibitors, may be needed to prevent the complications arising from the spectrum of clinical and metabolic abnormalities which arise from insulin resistance.

Effects of downhill running on the responses to an oral glucose challenge

Because muscle damage from eccentric exercise has been associated with alterations in muscle glycogen metabolism, this study determined the effects of exercise on the insulin and glucose responses to an oral glucose tolerance test (OGTT). In a repeated-measures design, 11 subjects undertook either no exercise, 2 min of isokinetic leg exercise, or 50 min of level or downhill running. No exercise was performed and diet was controlled during the 48 hrs after the treatments and before the OGTT. Ratings of muscle soreness and CK activity were significantly elevated 48 hrs after downhill running. Level running also increased CK activity but did not induce muscle soreness. Isokinetic exercise did not affect either one. Blood glucose responses to the OGTT were similar among the treatments. In contrast, the insulin responses to the OGTT following downhill running were significantly increased. These results suggest that eccentric exercise associated with downhill running that results in delayed muscle soreness is associated with the development of a mild insulin-resistant condition.

Effect of genetic dilution on development of diabetes, impaired glucose tolerance and in vitro glucose oxidation in LA/N-cp × SHR/N-cp F1 hybrid rats

1. To determine the effects of gene dilution on development of IGT, NIDDM and in vitro glucose oxidation, heterozygous lean LA/N-cp female and SHR/N-cp male rats were mated, and F1 offspring studied at periodic intervals to determine the prevalence of obese and diabetic traits. 2. Obesity occurred in 25% of offspring by 5 weeks of age, consistent with inheritance of the autosomal recessive cp trait. 3. IGT occurred in all obese male F1, 67% of obese female F1, and 18% of the lean male F1 rats by 5 months of age, and diabetes occurred in 80% of male obese and 17% of female obese rats from 6 months of age. Glycosuria occurred with glucose intolerance, and was more severe in rats with NIDDM than IGT. 4. Rates of in vitro glucose oxidation were greater in diaphragm and adipose tissue, and were greater in the presence of insulin (100 mu Units/ml) in obese female but not obese male F1 rats. 5. These results indicate that the development of glucose intolerance is more prominent in male than in female F1 rats, that the progression of IGT to NIDDM occurs later in life in the F1 hybrid than in the SHR/N-cp strain from which the diabetic trait was transmitted, and that genetic dilution of the diabetic trait via hybrid breeding results in a delay in the expression of NIDDM which is chronologically more similar to that which occurs in man.

Prevalence of abnormal glucose tolerance in six Solomon Islands populations

A survey of blood glucose levels in six Solomon Islands populations may support the hypothesis that susceptibility to diabetes is almost absent among non-Austronesian-speaking Melanesians regardless of their level of modernization. Among Austronesian-speaking Melanesians, however, diabetes is emerging. Differences in prevalence rates of diabetes between Austronesians and non-Austronesian speakers in this survey are significant (P less than .0001).

Diabetes mellitus: prevalence and local risk factors in a primary health care district

In the present comparative study of recent surveys the highest reported prevalence of diabetes mellitus in Sweden, 4.0% is found in the Kinda Primary Health Care District after age-standardization to that for the total Swedish population (3.3%). Even after critical evaluation of survey methods and diagnostic criteria, it appears that true regional differences in prevalence occur. Therapy traditions also differ, especially with elderly patients. No important local risk factor could be identified. A preventive programme is discussed. Any such programme must be based on current and future epidemiological data in a model comprising incidence, prevalence, mortality, and diabetic complications in order to be able to evaluate its effects.