To determine whether extracts of Gymnema sylvestre may have therapeutic potential for the treatment of noninsulin-dependent diabetes mellitus (NIDDM), we examined the effects of an alcoholic extract of G. sylvestre (GS4) on insulin secretion from rat islets of Langerhans and several pancreatic -cell lines. GS4 stimulated insulin release from HIT-T15, MIN6 and RINm5F -cells and from islets in the absence of any other stimulus, and GS4-stimulated insulin secretion was inhibited in the presence of 1 mM EGTA. Blockade of voltage-operated Ca 2+ channels with 10 µM isradipine did not significantly affect GS4-induced secretion, and insulin release in response to GS4 was independent of incubation temperature. Examination of islet and -cell integrity after exposure to GS4, by trypan blue exclusion, indicated that concentrations of GS4 that stimulated insulin secretion also caused increased uptake of dye. Two gymnemic acidenriched fractions of GS4, obtained by size exclusion and silica gel chromatography, also caused increases in insulin secretion concomitant with increased trypan blue uptake. These results confirm the stimulatory effects of G. sylvestre on insulin release, but indicate that GS4 acts by increasing cell permeability, rather than by stimulating exocytosis by regulated pathways. Thus the suitability of GS4 as a potential novel treatment for NIDDM can not be assessed by direct measurements of -cell function in vitro.

Objective:To determine the proportion of pre-hypertension and hypertension in college students in Kuwait and their related risk factors.Materials and Methods:A total of 803, randomly selected students aged 17 to 23 years (346 male, 457 female) from different colleges in Kuwait, were included in the study between 2009 and 2010. Systolic and diastolic blood pressure measurements were taken by trained personnel. Pre-hypertension was defined as systolic pressure between 120 and 139 mm Hg or diastolic pressure between 80 and 89 mm Hg. Risk factor measurements that were determined, included smoking, body mass index (BMI), and family history of hypertension. Blood samples were collected and impaired glucose tolerance (IGT) and lipid profile levels were determined.Results:There were no hypotensive students. Normotensives constituted 53.5% (n = 430), pre-hypertensives formed 39.5% (n = 317), and hypertensive students comprised of 7% (n = 56). The overall proportions of hypertension and pre-hypertension were higher among male students (85.7 and 64.4%) than female students (14.3 and 35.6%), respectively. Hypertensive and pre-hypertensive students versus normotensive students had significantly higher levels of BMI-based obesity, smoking, glycated hemoglobin (HbA1c), and IGT. Also, hypertensive and pre-hypertensive, compared to normotensive students, had significantly higher proportions (21.4, 18.3, and 4.0%, respectively) of risky high-density lipoprotein (HDL) level (< 1 mg / dL), cholesterol (7.1, 3.8, and 1.4%, respectively), and triglycerides (TG) (17.9, 9.1, and 7.9%, respectively) where p was< 0.001, 0.016, and 0.051, respectively.Conclusion:Hypertensive and pre-hypertensive students showed elevated levels of lipids and BMI-based obesity more than normotensive students. TG, HDL, HbA1c, and cholesterol appeared to influence pre-hypertension.

Objective: The objective of this study was to determine the prevalence of impaired glucose regulation in a young, asymptomatic Kuwaiti population. Subjects and Methods: A cross-sectional study of 484 Kuwaitis (females: 311, and males: 173, aged 17–24 years), students at a public college for basic education, was conducted. Each participant underwent a 75-gram oral glucose tolerance test, and biochemical testing for hemoglobin A_1c (HbA_1c), total cholesterol and triglyceride levels. Physical examinations were performed to measure body mass index (BMI), waist circumference and blood pressure. Results: The prevalence of impaired glucose regulation (impaired fasting glucose, impaired glucose tolerance, and elevated HbA_1c levels) was 32%, including 4% with newly diagnosed diabetes. Of the 484 participants, 47 (10%) of the population had hypertension and 52 (11%) had dyslipidemia. A total of 244 (50%) were classified as overweight/obese (BMI >25 kg/m²) and 201 (42%) had an elevated waist circumference (≧88 cm in females; ≧102 cm in males). Impaired glucose regulation was significantly related to increased waist circumference (p = 0.021) but not to increased BMI (p = 0.181). Those with impaired glucose regulation also had a higher prevalence of hypertension (p = 0.05), particularly systolic hypertension (p = 0.023). Conclusion: Kuwaiti youth have a high prevalence of impaired glucose regulation and overweight/obesity. Waist circumference, rather than BMI, may be a more appropriate screening tool to predict impaired glucose regulation in Kuwaiti youth.

The aim of this study was to investigate whether body mass index (BMI), eating habits and sedentary behaviours were associated with sleep duration among Kuwaiti adolescents. The study is part of the Arab Teens Lifestyle Study (ATLS), which is a school-based cross-sectional multi-center collaborative study. A sample of 906 adolescents (boys and girls) aged 14-19 years was randomly selected from 6 Kuwaiti Governances using a multistage stratified cluster sampling technique. The findings revealed that the prevalence of overweight and obesity was 50.5% in boys and 46.5% in girls. The majority of boys (76%) and of girls (74%) fell into the short sleep duration category (6 hours/day or less). Sleep duration were found to be negatively associated with BMI (girls only). Watching television (boys and girls) and working on computers (boys only) were also negatively associated with sleep duration. While the consumption of breakfast (both genders) and milk (boys only) was positively associated with sleep duration (p<0.05). In contrast, the consumption of fast foods (both genders), sugar-sweetened drinks and sweets (boys only) potatoes (girls only) were negatively associated with sleep duration (p<0.05). It can be concluded that the majority of Kuwaiti adolescents exhibit insufficient sleep duration which was associated with obesity measure, a combination of poor eating habits and more sedentary behaviors. The findings also suggest gender differences in these associations. Therefore, adequate sleep is an important modifiable risk factor to prevent obesity and was positively associated with some unhealthy lifestyle habits.

It has previously been suggested that ACTH and ACTHrelated peptides may act as paracrine modulators of insulin secretion in the islets of Langerhans. We have, therefore, examined the expression and function of the ACTH receptor (the melanocortin 2 receptor, MC2-R) in human and mouse primary islet tissue and in the MIN6 mouse insulinoma cell line. Mouse MC2-R mRNA was detected in both MIN6 cells and mouse islet tissue by PCR amplification of cDNA. In perifusion experiments with MIN6 pseudo-islets, a small, transient increase in insulin secretion was obtained when ACTH (1 nM) was added to medium containing 2 mM glucose (control) but not when the medium glucose content was increased to 8 mM. Further investigations were performed using static incubations of MIN6 cell monolayers; ACTH (1 pM-10 nM) provoked a concentration-dependent increase in insulin secretion from MIN6 monolayer cells that achieved statistical significance at concentrations of 1 and 10 nM (150 13·6% basal secretion; 187 14·9% basal secretion, P,0·01). Similar responses were obtained with ACTH 1-39 . The phosphodiesterase inhibitor IBMX (100 µM) potentiated the responses to sub-maximal doses of ACTH . Two inhibitors of the protein kinase A (PKA) signaling pathway, Rp-cAMPS (500 µM) and H-89 (10 µM), abolished the insulin secretory response to ACTH 1-24 (0·5-10 nM). Treatment with 1 nM ACTH 1-24 caused a small, statistically significant increase in intracellular cAMP levels. Secretory responses of MIN6 cells to ACTH 1-24 were also influenced by changes in extracellular Ca 2+ levels. Incubation in Ca 2+-free buffer supplemented with 0·1 mM EGTA blocked the MIN6 cells' secretory response to 1 and 10 nM ACTH 1-24 . Similar results were obtained when a Ca 2+ channel blocker (nitrendipine, 10 µM) was added to the Ca 2+ -containing buffer.ACTH 1-24 also evoked an insulin secretory response from primary tissues. The addition of ACTH 1-24 (0·5 nM) to perifusions of mouse islets induced a transient increase in insulin secretion at 8 mM glucose. Perifused human primary islets also showed a secretory response to ACTH 1-24 at basal glucose concentration (2 mM) with a rapid initial spike in insulin secretion followed by a decline to basal levels. Overall the results demonstrate that the MC2-R is expressed in -cells and suggest that activation of the receptor by ACTH initiates insulin secretion through the activation of PKA in association with Ca 2+ influx into -cells.