مجله دیابت و متابولیسم ایران
پیاپی 2 (بهار و تابستان 1381)

The incidence and prevalence of type2 diabetes mellitus is increasing worldwide. Many believe that type 2 diabetes mellitus is a disease that can be prevented by appropriate interventions in individuals at high risk for the disease. A number of studies have therefore looked at primary prevention during the past decade. Iran’s diabetic population of approximately 2 million people and the warning by the World Health Organisation that diabetes is on the rise in developing countries make the primary prevention of diabetes mellitus in Iran doubly important. Researchers have been increasingly focusing on identifying the risk factors for type 2 diabetes and, through these, appropriate strategies to prevent the rapidly growing incidence of this disease in the population at risk. Genetic predisposition (a positive family history), insulin resistance, obesity, impaired glucose tolerance, a history of gestational diabetes mellitus, physical inactivity and an unsuitable diet are among the most important recognised risk factors for type 2 diabetes; other factors have also been found to contribute. Most of the available research has evaluated the effect of behavioural or lifestyle modification, in the form usually of dietary education and increased physical activity, in the primary prevention of type 2 diabetes. The second most common approach has been pharmacological manipulation. The information available indicates that type 2 diabetes will come to be considered as a preventable disease within the next decade. The weight of research behind this problem will undoubtedly discover even more effective methods of preventing type 2 diabetes in the near future than behavioural/lifestyle modification.

There are more than 140 million people with diabetes in the world. Iran’s share is estimated at 1.5 million people. The increasing prevalence of diabetes and the longer life expectancy of diabetic patients mean that an increasing number of patients with diabetes are undergoing surgery, and not just for diabetes and its complications, such as end-stage renal disease, retinopathy, peripheral vascular disease, and diabetic foot ulcers. The metabolic stress caused by general anaesthesia and the operation itself makes blood glucose control even more difficult. Stricter pre- and intra-operative glycaemic control reduces the risk of sepsis, cardiovascular events, disability and death, accelerates wound healing and decreases hospital stay. Improved outcome requires pre-operative ascertainment of the type of diabetes, quality of metabolic control, and detection of complications, as well as optimal metabolic and haemodynamic management during the operation. Local anaesthesia is the preferred option in this group of patients because it least interferes with metabolic control. The diet recommended to achieve normoglycaemia will depend on the type of diabetes, pre-operative glycaemic control, and the extent of the planned procedure. In all type 1 diabetic patients and type 2 diabetic patients on insulin or oral hypoglycaemic agents who are to undergo surgery under general anaesthesia, the glucose-insulin-potassium (GIK) regimen is the one recommended by most authors to achieve tight intra-operative blood glucose control, conditional upon blood glucose measurements being available every one or, at most, two hours. Intra-operative blood glucose levels in the 120-180mg/dl ranges are considered satisfactory. Failing this, it is recommended that 50% of the daily NPH requirement be given subcutaneously on the morning of the operation, together with an intravenous glucose infusion intra-operatively. Type 2 diabetic patients with unsatisfactory metabolic control, time permitting, should be admitted several days before the operation and switched to and stabilised on insulin.

In this study, we compared the level of glycosylated haemoglobin in patients with essential hypertension and healthy controls. 70 non-diabetic patients with essential hypertension were recruited into the study along with 140 controls without any significant medical history. Persons with a history of metabolic disease, anaemia, renal disease, splenectomy, pregnancy, or on medication were excluded from the study. A blood sample was taken from each participant and immediately sent to the EEMRC laboratory, where fasting blood sugar and glycosylated haemoglobin levels were measured by the glucose oxidase and thiobarbituric acid (colorimetry) method, respectively. The unpaired t-test was used to compare means. A p-value of less than 0.05 was considered significant. Mean fasting blood glucose was 103.1±16.1mg/dl in the hypertensive group and 92±7mg/dl in controls (p<0.05). Mean glycosylated haemoglobin levels were 7.38±0.78% in the hypertensive group and 6.5±0.85% in controls (p<0.05). People with essential hypertension have a higher level of glycosylated haemoglobin than healthy controls.

The prevalence of type 2 diabetes is increasing daily all around the world and is a serious threat to the well-being of the community in terms of renal failure, cardiovascular disease, blindness, and neuropathy. The assessment of difference screening approaches is of great importance in this disease. We compared ADA and WHO criteria for the diagnosis of type 2 diabetes. 982 individuals (age range: 30 to 64 years), residents of the city of Bushehr, were chosen by systematic random sampling for this study, each providing a fasting blood sample for a standard oral glucose tolerance test. Plasma glucose was measured by the glucose oxidase-peroxidase method, using a Technikon RA1000 autoanalyser. Data was analysed with the Chi-squared and Student’s t tests and, when required, Fisher’s Exact test. 354 (36%) men and 628 (64%) women took part in this study. 42.9% were in the 30-39 age group. 69 (20 men and 49 women) of the 982, that is 7% of the sample, had known diabetes before recruitment into the study. The crude prevalence of type 2 diabetes and impaired glucose tolerance using WHO criteria was 13.6 and 15.6 percent, respectively. The crude prevalence of type 2 diabetes using ADA criteria was 13.4 percent. 51% of patients were already aware of their disease. The sensitivity of fasting blood glucose testing for detecting diabetes was 45.8% using WHO and 62.5% using ADA criteria. Both sets of criteria were equally specific. Given the overall prevalence of glucose intolerance (impaired glucose tolerance and type 2 diabetes) in Bushehr, it should be considered as a high-prevalence area for diabetes. Accordingly, we recommend screening with fasting plasma glucose and oral glucose tolerance testing.

In order to determine the relationship between serum lipid profile and diabetes mellitus as well as other cardiovascular risk factors, we carried out a cross-sectional study of 1255 oil industry workers at the Kharg Island oil terminal. Increased levels of total cholesterol (TC≥200mg/dl), triglyceride (TG≥200mg/dl), and low-density lipoprotein (LDL≥130mg/dl) were seen in 32.7%, 39.5% and 18.5% of the workers, respectively. Decreased levels of high-density lipoprotein (HDL<40mg/dl) were seen in 13.1% of workers. 61.3% of the workers had a body mass index (BMI) ≥25kg/m2. Visceral obesity (waist circumference >100cm) was seen 32.4% of workers. There was a direct and significant relationship between TC levels and BMI (p<0.001), and between TG levels and BMI (p<0.0001). The same correlation existed between waist circumference and both TC (p<0.02) and TG (p<0.06). There was also a direct correlation between LDL levels and waist circumference (p<0.04). 10.6% of workers had some disorder of glucose metabolism. There was a direct correlation between diabetes and both TC and HDL levels (p<0.04 and p<0.05, respectively). 42.4% of workers smoked and 57.4% had a sedentary lifestyle. There was a trend toward lower blood glucose and cholesterol levels as the level of physical activity increased (p=0.1 and p=0.08, respectively). There was a significant difference between blue- and white-collar workers in the prevalence of excess weight, visceral obesity, diastolic hypertension, diabetes and cigarette smoking, but not serum lipid profile and level of physical activity. The significant prevalence of dyslipidaemia and other cardiovascular risk factors in the oil workers of Kharg Island requires systematic preventive interventions to reduce cardiovascular mortality and morbidity in this population.

In patients with type 2 diabetes, triglyceride (TG) is usually increased, HDL decreased, and LDL normal. This pattern is associated with an increased risk of coronary heart disease. More recently, dense-particle LDL has been identified as an important risk factor for coronary heart disease. 298 patients with type 2 diabetes attending the diabetes clinic at Doctor Shariati University Hospital underwent anthropometric and biochemical assessment. Anthropometric measurements followed WHO criteria. Biochemical indices (apoB100, TG, cholesterol, LDL, LDL particle size, HDL, and apoA1) were measured using standard laboratory methods. One-way ANOVA was used to analyse data with SPSSv6 software. Mean patient age was 55±13.2 years. Mean duration of diabetes was 9.5±6.1 years. The majority of patients were moderate to severely overweight. 73.2% of patients had some form of hyperlipidaemia. 20.7% had isolated hypertriglyceridaemia, 21% isolated hypercholesterolaemia, and 31.5% mixed hyperlipidaemia. Mean apoA1 concentration was higher than normal in this group, and mean apoB100 concentration lower. LDL particle size generally followed a small and dense pattern. This study shows that LDL particles in both men and women with type 2 diabetes undergo both qualitative and quantitative changes. 35.5% of patients had smaller, denser LDL particles than normal. It appears that dyslipidaemia and B-pattern LDL particles are important risk factors for atherosclerosis in this group.

Anethum is an herbal medicine composed of the three plants species Anethum, Fumaria and Cichorium, and has been widely marketed and prescribed as lipid-lowering agent in Iran in recent years. No controlled clinical trial of this medicine has so far been carried out, however. We studied the efficacy and short-term side effects of Anethum in patients with isolated hypertriglyceridaemia. 151 people (54 men and 97 women) with serum triglyceride ≥250mg/dl and serum cholesterol <240mg/dl were enrolled in this study. Participants were randomly assigned to one of four treatment groups: Anethum, nicotinic acid, clofibrate, and placebo. They were seen at the Doctor Shariati University Hospital lipid clinic once every two weeks. Serum lipid profile was measured at 2 and 4 months after start of therapy. Relevant patient details, including sex, body mass index, mean total cholesterol and high-density lipoprotein, cigarette smoking, previous myocardial infarction, physical activity, and oral contraceptive use were recorded before enrolment. Four months after treatment was started, serum triglyceride had decreased 12.5% in the Anethum group and 6.8% in the placebo group (p=0.999). During the same period, serum triglyceride had decreased 48.8% in the nicotinic acid group and 54.4% in the clofibrate group (p=0.006 with respect to both placebo and Anethum). Furthermore, the nicotinic acid group showed a 7.8% decrease in serum total cholesterol (p=0.009 with respect to the other three groups). HDL-C decreased 9.8% in the Anethum group, 17.5% in the nicotinic acid group, 8.1% in the clofibrate group, and 9.1% in the placebo group (p=0.149 between first three groups and placebo). 81.8% of the nicotinic acid, 57.1% of the clofibrate, 8.0% of the Anethum and 30% of the placebo group experienced side effects during the same period. The most common complaints in the Anethum were actually non-specific ones. We conclude that Anethum does not exert any therapeutic effect on isolated hypertriglyceridaemia.

There is as yet no consensus as to the effect of Ramadan fasting on fasting blood glucose. We carried out a study to help clarify the situation. This was a semi-experimental (pre- and post-) study of 115 healthy volunteers (67 men and 48 women), who fasted for at least 25 days during Ramadan. Blood samples were taken 7 days before Ramadan (at 7am after a 8-hour overnight fast), and on the 14th and 28th days of Ramadan (1 hour before sundown). The mean duration of daily fasting was 11.5±0.5 hours. Plasma glucose was measured by an enzymatic assay. Statistical analysis was by the paired-t and ANOVA functions on SPSS10.0 software. Fasting plasma glucose in the group as a whole decreased from 88.4±9.0mg/dl pre-Ramadan to 75.4±15.3mg/dl on day 14 and 62.9±7.7mg/dl on day 28 (p<0.001). Both men [87.5±8.8mgdl (pre-Ramadan)  60.8±6.4mg/dl (day 28)] and women [89.7±9.3mgdl (pre-Ramadan)  65.7±8.4mg/dl (day 28)] experienced a significant decrease in fasting plasma glucose levels (p<0.001 in both). There was a reduction in calorie intake during Ramadan in every volunteer (p<0.001), and there was a direct correlation between reduction in calorie intake and fasting plasma glucose (p<0.01). Fasting plasma glucose decreases with Ramadan fasting and is associated with a reduction in calorie intake. The decrease in plasma glucose does not seem to be accompanied by any serious adverse effects in healthy volunteers, however.

The urinary excretion of minimal quantities of albumin (microalbuminuria) is predictive of renal failure and cardiovascular mortality. The detection and prompt treatment of microalbuminuria is crucial to the prevention and progress of renal failure in patients with diabetes. The aim of this study is to evaluate the relative frequency of microalbuminuria in different age groups of men and women attending the diabetes clinic at Imam Khomeini University Hospital. 123 patients each provided a 12-hour urine sample, collected in standard fashion. Urinary albumin was measured by immunoturbidometry. The frequency of microalbuminuria (urinary albumin excretion between 30mg and 300mg in a 24-hour sample) was assessed in different age groups in men and women, according to duration of diabetes, glomerular filtration rate (GFR), glycosylated haemoglobin levels (A1C), body mass index (BMI), and both systolic and diastolic blood pressure. Overall, 20.3% of patients had microalbuminuria, 61.1% normoalbuminuria, and 10.6% macroalbuminuria. Patients with microalbuminuria were significantly older (mean age = 58.5 years) than patients with normal albumin excretion (50.3 years). The male-to-female ratio was highest in patients with microalbuminuria and lowest in those with normoalbuminuria. There was no significant difference in GFR, A1C, and blood pressure between patients with normo-, micro-, or microalbuminuria. There was a significant difference in duration of diabetes between normoalbuminuric (9.3 years) and microalbuminuric patients (11.5 years). There was a significant, inverse correlation between BMI and urinary albumin excretion. Renal function in patients with type 2 diabetes deteriorates with increasing age and duration of diabetes. Renal impairment is more common in men than women.

Gestational diabetes mellitus (GDM) is defined as carbohydrate intolerance occurring or detected for the first time during pregnancy. Hypertension occurring as a result of pregnancy is called pregnancy-induced hypertension (PIH), which is itself divided into two groups: gestational hypertension and pre-eclampsia. The aim of this study is to compare the incidence of hypertensive disorders in patients with GDM and controls. This is a case-control study of 2416 pregnant women attending 5 antenatal clinics attached to Tehran University of Medical Sciences. The universal two-step screening approach was used: first, all women underwent a 50-gram 1-hour glucose challenge test; second, all women with a 1-hour blood glucose concentration higher than 130mg/dl underwent a 100-gram, 3 hour oral glucose tolerance test. Carpenter and Coustan’s criteria were used to diagnose GDM. 220 women with a normal glucose challenge test were chosen as controls. GDM cases and controls were matched for age, body mass index, parity, and gestational age. 114 women overall were diagnosed with GDM. Mean age, BMI, and parity in GDM and control groups were 29.09±6.13 and 28.64±6.00 years, 27.43±4.33 and 26.64±1.8 kg/m2, and 1.79 and 1.52 births, respectively. Women with GDM had a higher prevalence of essential hypertension, PIH, and pre-eclampsia than matched controls. Our results show that hypertensive disorders are more common in women with GDM than in normoglycaemic controls of similar age, parity and BMI.