مجله دیابت و متابولیسم ایران
سال چهارم شماره 3 (پیاپی 9، بهار 1384)

Leptin is a 16-kD protein which is secreted from white adipocytes and, its discovery has generated enormous interest in the regulation of energy balance. Leptin has been implicated in the regulation of food intake, energy expenditure, and whole-body energy balance in animals and human. Plasma leptin levels correlate with fat storages and respond to changes in energy balance. It was initially proposed that leptin serves a primary role as an anti-obesity hormone, but this role is commonly thwarted by leptin resistance. The profound effects of leptin on regulating body energy balance, make it as a prime candidate for drug therapies of obesity in humans and animals. Despite the recent achievements in unearthing the role of leptin in the pathophysiology of obesity, many important questions still remained that must be responded. More studies with follow-up designs and genetic evaluations are warranted to understand the comprehensive role of leptin in human. In this letter we have a review of known effects of leptin on human obesity up to now.

The role of nucleus tractus solitarius in cardiovascular system regulation is controversial. On the other hand, study on the problem of hypertension in diabetic animals is the subject of many research programs. The aim of the present study was to determine wheather inactivation of nucleus can affect blood pressure in diabetic rats. To this end, stereptosotocin-induced diabetic rats were anesthetized with Urethane and a cannula was inserted above nucleus. Blood pressure and heart rate were monitored using an intraarterial cannula. The cannulas were filled with L-glutamate (78 pmol/60 nL, to functionally identify the NTS; see below), L-NAME(1nmol, to inhibit the nitric oxidergic neurons) and sodium nitroprusside (100mmol,as a NO-donor). The results indicated that inactivation of nucleus in diabetic rats, had no effect on systolic and mean arterial pressure but enhanced diastolic blood pressure (P<0.05). There was no significant difference in heart rate between control and test groups. Glucose affect on increasing blood pressure in rats with induced diabetes, in part, is caused by nitric oxidergic neurons resided in neucleus tractus solitarius.

All contemporary methods of insulin administration are non-physiological. Insulin is not absorbed from the gastrointestinal tract because of its peptide nature. The aim of the present study was to examine the absorption of oral insulin from gastrointestinal tract, using novel oral formulation- adding a delivery agent superporouse hydrogel (SPH) and SPH composite (SPHC) in combination with insulin. Capsules containing insulin and SPH &SPHC were administered orally, to 15 non-diabetic subjects in order to assess its biological effects and safety. Plasma glucose, insulin and c – peptide serum levels were determined, at timed intervals up to 4 h. In the present study, we showed that AUC of exogenous insulin in polymer -insulin group was higher than sub-cutaneous regular insulin group. It means that addition of SPHC polymer caused increase in insulin absorbtion.In addition, Insulin Tmax in polymer group was longer than sub-cotaneaus insulin group. Blood glucose AUC in sub-cotaneaus group was higher than polymer group.AUC C-peptide serum level in polymer group was higher than sub-cutaneous group. Insulin in combination with a novel delivery agent, SPH and SPHC, given orally is absorbed through the GI tract in a biologically active form. This was demonstrated by suppression of endogenous insulin secretion.

The importance of feed controlling has been proved in metabolic control of diabetic patients. An appropriate metabolic control prevents later complications. Patients with diabetes mellitus are deprived from eating sweat foods. Considering the effect of different carbohydrates on blood sugar, physicians and patients confront a lot of questions about eating these foods. The aim of this study was to compare the effect of sugar cube and Date consumption on blood sugar in patients with type 1 diabetes. As a clinical-trial, we selected 20 patients with type I diabetes mellitus sequentially. They were divided into two groups with 10 subjects in each group. The patient’s blood sugar was measured in 2 days with one week interval, before and after eating a Date (10gr) and a sugar cube (5gr). We measured blood sugar at 30, 60, 90 and 120 minutes after consumption. Data analysis was performed by SPSS software version 11, and the results were compared by paired t test. There was no significant difference between the blood sugar after eating Date and sugar cube. We also compared the surface under the curve of blood sugar after eating date and sugar cube in 2 hours, which was 1619.4 ± 614 mg.min/dL and 1572 ± 967 mg.min/dL for sugar cube and Date respectively, which the difference was not significant. Rising in blood sugar after Date consumption has not significant difference in comparison with sugar cube consumption in patients with type I diabetes. So, eating Date in diabetic patients is not preferable to eating sugar cube.

Mitochondria is one of the intracellular organelle with specific DNA. Some diseases caused by mtDNA mutations have been reported up to now. Mutation of A3243G and deletion of 5kb are two of them that related to Diabetes type II. The aim of this study was to evaluate the frequency of A3243G mutation and 5kb mt DNA deletion in type II diabetic patients. The DNA extracted from blood of 130 patients with diabetes type II. Serum insulin of the patients were also measured. Sequence assigning, PCR – RFLP and SSCP methods were used to detect the A3243G or other mutation in mitochondrial tRNA (leu) gene. Standard and multiplex PCR were used to detect 5kb deletion in patient’s mt DNA and were compared with 40 healthy persons. We couldn’t identify any deletion of 5kb or A3243G point mutation in our patients but SSCP results showed new pattern of PCR Product in patients. An “A” nucleotide deletion in A 3314 position was detected in mitochondrial ND1 gene in 6 patients. So far this point deletion has not been reported. Identification of the mitochondrial gene mutations helps to preclinical diagnosis of diabetes type 2. More research is necessary in this field.

Cardiovascular diseases are the first cause of death in Iran and hypercholesterolemia is one of the most important risk factors. This problem could be partially managed by dietary modifications such as supplementation of diet with dairy products and probiotic bacteria. The aim of this study was to comprise the effect of consuming a probiotic yoghurt and ordinary yoghurt on serum cholesterol levels in mild to moderate hypercholesterolemia. This randomized cross-over trial was conducted on 14 healthy subjects aged 40-65 years with total serum cholesterol 200-300 mg/dl. We asked the subjects to avoid consumption of yoghurt for a two-week pre-study period and add 300 g/day of milk to their diet. Then they were randomly allocated to 2 groups to receive either 300 g of ordinary yoghurt (fermented with S.thermophilus and L.bulgaricus) or probiotic yoghurt (fermented with a starter composed of L.acidophilus and B.lactis plus bacteria in ordinary yoghurt) for 6 weeks as substitution for milk. After a wash-out period of 7 weeks, the cross-over was made (those consuming probiotic yoghurt, changed to ordinary yoghurt and vice versa) and the study lasted for another 6 weeks. Anthropometric measurements, a 3-day dietary recall and blood lipid tests were done at the beginning (after a 2-week elimination period of yoghurt from diet) and at the end of each period. Comparison of weights, BMIs and dietary confounding factors during the period of consuming ordinary yoghurt and probiotic yoghurt, did not show any significant differences. Consumption of probiotic yoghurt in comparison with ordinary yogurt caused a significant decrease in total serum cholesterol (P=0.049). Comparison of other blood lipid criteria did not show any significant differences between these two periods. Consumption of the yoghurt containing two probiotic bacteria, L.acidophilus and B.lactis, in comparison with ordinary yoghurt causes reduction in total serum cholesterol in mild to moderate hypercholesterolemia.

Several studies and research have shown a higher prevalence of celiac disease (CD) and elevation of serum antibody (AGA-IgA & IgA-tTG & EMA-IgA) in patient with diabetes mellitus type I (T1DM) in versus general and non-diabetic population. Thus screening of CD is recommended in T1DM). This study was conducted to compare frequency of celiac disease in patients with T1DM and healthy persons. As a case-control study,60 patient with T1DM that reffered to endocrine clinic of Qazvin’s Boo-Ali hospital, in nearly one year period were enrolled as case group. 60 non-diabetic healthy subjects with age and sex matched, were selected as control group. Blood levels of Total IgA, AGA-IgA and IgA-tTG were measured in all of them, subjects who had elevated of both AGA-IgA and IgA-tTG underwent an upper GI endoscopy and biopsy was done from distal part of duodenum. Any one in case group hadnt IgA deficiency. 14 subjects in control and 12 subjects in case group had positive AGA-IgA that there was no significant difference between them. 2 subject of case group had positive IgA-tTG. Duodenal biopsy in 1 of 14 cases who had elevated AGA-IgA)1 of 2 cases who had elevated IgA-tTG), revealed total villous atrophy indicating CD (Type IIIC with revised Marsh criteria 2001) and in other cases pathologic findings were normal or with nonspecific changes. Frequency of CD in T1DM in our study is 1.67%. There is not any significant difference between case and control groups in prevalence of Celiac disease. But we conclused that screening with AGA-IgA is not a reliable screening test for CD, because there is not significant difference between T1DM and general population.

a variety of studies have noted seasonal variation in blood lipid levels, yet the mechanism for this phenomenon has not been clear. This leads to significant difference in prevalence of lipid disorders in different seasons. A cross sectional study conducted on 6894 individuals (2890 men and 4004 women) aged 20-64 years who participated in the 1st phase of Tehran Lipid and Glucose study from March 1999 to September 2001. The mean level of plasma lipid values was compared between seasons by ANCOVA after adjustment for age, physical activity, smoking, BMI and waist-to-hip ratio. The sex specific prevalence of lipid disorders in summer and winter was calculated. 58% of participants were women. The mean age of men and women was 38.3±11.3 and 39.4±11.6 respectively (P=0.13). There was a significant seasonal variation in serum total cholesterol, LDL-C and HDL-C in men (P<0.05) with a peak in winter and a trough in summer (P<0.05). In women, only triglyceride levels showed significant seasonal variation characterized by increase in summer and decrease in winter (P<0.05). In men, there was 26.2% increase in prevalence of hypercholesterolemia (>240 mg/dl) in winter compared to summer (P<0.05). The corresponding increase in level of high risk LDL-C (≥160 mg/dl) was 26.7% and 24.9 % in men and women respectively (P<0.05). There was 23.8% decrease in the prevalence of hypertriglyceridemia (>200 mg/dl) in winter compared to summer in women (P<0.001). This study confirms seasonal variation in blood lipid levels and suggests greater amplitude in seasonal variability in men than women. On the other hand, the increase in the prevalence of high risk LDL-C in both genders in winter should be considered in patients screening and follow-up strategies.

Prevalence of obesity is increasing globally, and it is proved that obesity is associated with cordiovascular diseases, type II diabetes, hypertension, dyslipidemia and breast cancer. This study was carried out among 150 female students of Shadid Beheshti university who were resided in Velekjad dormitory, in order to assess the rate of obesity among them. As a cross-sectional study; height, weight, waist circumference and hip circumference were measured. Food frequency and socioeconomic questionnairs were completed. BMI and WHR were used to assess the general and central obesity respectively. Mean standard deviation of age, BMI, WHR, WC were 260 31 (months), 21.42 2.56 (kg/m2), 0.79 0.04 and 75.71 7.10 (cm) respectively. Among subjects, 40.5% had WHR more than 0.8, 9.3% were overweight, 62.1% normal and 28.6% underweight. Of whom, 37.8% werent exercising at all. There was a negative correlation between BMI and consumption of butter, milk, meat (p<0.001 for all) and egg (p<0.01), between WHR and consumption of egg and butter (p<0.01 for both of them) and also between WC and cosumption of butter (P<0.001) and milk (P<0.01). Although prevalence of general obesity among the subjects was low, central obesity (based on WHR) was significant, so lifestyle modifications such as nutritional changes and increase physical activity among students is recommended.

Diabetes mellitus is one of the chronic metabolic diseases with several organ damages that dearese life span. Prevalence of known diabetes appears to be increasing in most countries, presumably due to increasing the prevalence of risk factors such as obesity, lower physical activity and improved diagnosis. WHO expect the number of adults (20 years and older) with diabetes rises up to 300 millions in 2025. In view of the worldwide geographic differences in diabetes and lack of documented informations about prevalence of diabetes in Iran, we assigned this study. The base of our study for assessment of prevalence of diabetes in Iran was results of ״Health and Disease Study in Iran, 1999״. We used epidemiologic model (DisMod) for estimating the incidence of diabetes in Iran. The prevalence of diabetes in over 20 years of Iranian population in 2000, was 1. 6 million or 4. 67%. Also it is estimated up to 100000 persons have been affected by type II diabetes. The true limitation of our study was limitations of documents about estimated of proportion of true prevalence to prevalence of known diabetes.