Supamai Soonthornpun

Postprandial plasma glucose: a good index of glycemic control in type 2 diabetic patients having near-normal fasting glucose levels.

To investigate the effect of postprandial plasma glucose (PG) concentrations on HbA1c levels in type 2 diabetic patients, we evaluated the relationship between HbA1c levels and postprandial PG concentrations after a meal tolerance test in 35 type 2 diabetic patients who had fasting PG concentrations persistently < 7.8 mmol/l and stable HbA1c levels. Two-hour postprandial PG concentrations were found to be more strongly correlated (r = 0.51) with HbA1c levels than 1-h postprandial PG (r = 0.35) and fasting PG (r = 0.46) concentrations. Patients whose HbA1c levels were high (HbA1c > or = 7%) had significantly higher 2-h postprandial PG concentrations and areas under the glucose curve than those whose HbA1c levels were lower (8.12+/-1.10 (SD) vs 6.70+/-2.22 mmol l(-1), P = 0.004 and 17.43+/-1.92 vs 15.58+/-3.26 mmol h(-1) l(-1), P = 0.02, respectively). Although fasting PG concentrations of patients with higher HbA1c levels were slightly higher, they did not differ significantly from those with lower HbA1c levels (6.21+/-0.89 vs 5.73+/-0.68 mmol l(-1)). Age, duration of diabetes, body mass index, serum C-peptide, both fasting and postprandial, did not differ between these two groups. This study suggests that postprandial hyperglycemia, particularly 2-h postprandial PG concentrations, is associated with high HbA1c levels in type 2 diabetic patients whose fasting PG levels were within normal or near-normal levels.

Regional Abdominal Fat Distribution in Lean and Obese Thai Type 2 Diabetic Women: Relationships With Insulin Sensitivity and Cardiovascular Risk Factors

To determine the relationships of body fat distribution and insulin sensitivity and cardiovascular risk factors in lean and obese Thai type 2 diabetic women, 9 lean and 11 obese subjects, with respective mean age 41.7 +/- 6.3 (SD) and 48.0 +/- 8.5 years, and mean body mass index (BMI) 23.5 +/- 1.8 and 30.3 +/- 3.7 kg/m2, were studied. The amount of total body fat (TBF) and total abdominal fat (AF) were measured by dual-energy x-ray absorptiometer, whereas subcutaneous (SAF) and visceral abdominal fat areas (VAF) were measured by computerized tomography (CT) of the abdomen at the L4-L5 level. Insulin sensitivity was determined by euglycemic hyperinsulinemic clamp. Cardiovascular risk factors, which included fasting and post-glucose challenged plasma glucose and insulin, systolic (SBP) and diastolic blood pressure (DBP), lipid profile, fibrinogen, and uric acid, were also determined. VAF was inversely correlated with insulin sensitivity as determined by glucose infusion rate (GIR) during the clamp, in both lean (r=-0.8821; P=.009) and obese subjects (r=-0.582; P=.078) independent of percent TBF. SAF and TBF were not correlated with GIR. With regards to cardiovascular risk factors, VAF was correlated with SBP (r=0.5279; P=.024) and DBP (r=0.6492; P=.004), fasting insulin (r=0.7256; P=.001) and uric acid (r=0.4963; P=.036) after adjustment for percent TBF. In contrast, TBF was correlated with fasting insulin (r=0.517; P=.023), area under the curve (AUC) of insulin (r=0.625; P=.004), triglyceride (TG) (r=0.668; P=.002), and uric acid (r=0.49; P=.033). GIR was not correlated with any of cardiovascular risk factors independent of VAF. In conclusion, VAF was a strong determinant of insulin sensitivity and several cardiovascular risk factors in both lean and obese Thai type 2 diabetic women.

Insulin resistance in subjects with a history of thyrotoxic periodic paralysis (TPP)

Background  Hyperinsulinaemia has been suggested as an important factor for developing hypokalaemic paralysis in patients with thyrotoxic periodic paralysis (TPP). Since hyperinsulinaemia is a common feature of insulin resistance, there may be a causal relationship between insulin resistance and TPP.

Relationships of body fat distribution, insulin sensitivity and cardiovascular risk factors in lean, healthy non-diabetic Thai men and women

In order to study the relationships of body fat distribution, insulin sensitivity and cardiovascular risk factors in lean, healthy non-diabetic Thai men and women, 32 healthy, non-diabetic subjects, 16 men and 16 women, with respective mean age 28.4+/-6.6 (S.D.) and 32.8+/-8.9 years, mean BMI 21.0+/-2.8 and 21.2+/-3.7 kg/m(2), were measured for total body fat and abdominal fat by dual energy X-ray absorptiometry (DEXA), anthropometry and insulin sensitivity by euglycemic hyperinsulinemic clamp. Cardiovascular risk factors included fasting and post-glucose challenge plasma glucose and insulin, blood pressure, lipid profile, fibrinogen and uric acid. For similar age and BMI, men had a lower amount and percent of total body fat, but had a higher proportion of abdominal/total body fat than women. In men, insulin sensitivity, as determined by glucose infusion rate during euglycemic hyperinsulinemic clamp, was inversely correlated with total body fat, abdominal fat, BMI and waist circumference, whereas only total body fat, but not abdominal fat, BW and hip circumference were inversely correlated with insulin sensitivity in women. No cardiovascular risk factors, except area under the curve (AUC), of plasma insulin in women correlated with insulin sensitivity when adjusted for total body fat. After age adjustment, total body fat was better correlated with fasting and AUC of plasma glucose and insulin in men and with systolic blood pressure as well as triglyceride levels in women. Only HDL-C in men was better correlated with abdominal fat. In conclusion, there were sex-differences in body fat distribution and its relationship with insulin sensitivity and cardiovascular risk factors in lean, healthy non-diabetic Thai subjects. Total body fat was a major determinant of insulin sensitivity in both men and women, abdominal fat may play a role in men only. Body fat, not insulin sensitivity, was associated with cardiovascular risk factors in these lean subjects.

A comparison between a 75-g and 100-g oral glucose tolerance test in pregnant women.

Objectives: To test the validity of a 75‐g, 2‐h oral glucose tolerance test (OGTT) for diagnosing gestational diabetes mellitus (GDM) using the criteria and reference values suggested by the American Diabetes Association for the 100‐g, 3‐h OGTT. Methods: The results of a 75‐g, 2‐h OGTT were compared with those of a 100‐g, 3‐h OGTT in 42 pregnant women. The womens mean±S.D. age and gestational age were 33.6±5.4 years and 28.2±4.2 weeks, respectively. Each subject was randomly scheduled within 1 week for both the 75‐g and 100‐g OGTTs. Results: The mean plasma glucose concentrations at 1, 2, and 3 h during the 100‐g OGTT were significantly higher than those during the 75‐g OGTT. Using the Carpenter and Coustan criteria, the prevalence of GDM was 21.4% when using the 100‐g, 3‐h OGTT, whereas it was found to be at only 7.1% when using the 75‐g, 2‐h OGTT. Conclusions: Plasma glucose responses during the 75‐g OGTT were found to be lower than those during the 100‐g OGTT. When using the same diagnostic criteria, the prevalence of GDM was also found lower using the 75‐g glucose load. It would therefore not be appropriate to use the 75‐g OGTT for diagnosing GDM using the criteria and reference values of the 100‐g OGTT. To give a comparable prevalence of GDM, the threshold of abnormal plasma glucose levels of the 75‐g OGTT would need to be lower than that of the 100‐g OGTT.

Insulin resistance in women with a history of severe pre-eclampsia.

Aim:  This study investigated whether post‐partum insulin resistance existed in women with a history of severe pre‐eclampsia.

Causes of death, incidence and risk factors of cardiovascular diseases in Thai type 2 diabetic patients: a 5-year follow-up study

There appear to be ethnic disparities in frequencies of diabetic complications in type 2 diabetic patients and such data from Asian countries are relatively few and limited. Thai type 2 diabetic patients who attended the diabetic clinic at Prince of Songkla University hospital during January-December 1997 and had no history of coronary heart disease (CHD) and stroke were studied to determine cause of death and to establish the incidence of and risk factors for cardiovascular disease (CVD). All patients were followed to death or to the end of year 2001. End-points included death from any cause, fatal and nonfatal CHD, fatal and nonfatal stroke and lower-extremity amputation. There were 229 patients who were followed for 4.2+/0.7 (S.D.) years (range: 0.6-5.0) with total follow-up period 958.2 patient-years. Twenty-nine patients died during follow-up; the total mortality rate was 30.3 (95%CI 20.2-43.4)/1000 patient-years. Of these, 9(9.4/1000 patient-years; 95%CI 4.3-17.8) died from sepsis, 7(7.3/1000 patient-years; 95%CI 2.9-15.0) from CVD, 5(5.2/1000 patient-years; 95%CI 2.7-12.2) from end-stage renal disease, 3(3.1/1000 patient-years; 95%CI 0.6-9.2) from malignancy and 1(1.0/1000 patient-years; 95%CI 0.03-5.8) from peripheral vascular disease. The incidences of fatal and nonfatal CHD as well as fatal and nonfatal stroke were 21.4(95%CI 13.0-33.0)/1000 and 12.8(95%CI 6.6-22.4)/1000 patient-years, respectively whereas the incidence of lower-extremity amputation was 4.3(95%CI 1.2-10.9)/1000 patient-years. Age, the presence of proteinuria and serum HDL-C < or = 0.9 mmol/l were independent risk factors of CHD with the respective Hazard ratios 1.09(95%CI: 1.02-1.17; P=0.016), 4.41(95%CI: 1.18-16.45; P=0.027) and 3.91(95%CI: 1.20-12.80; P=0.024). In conclusion, sepsis and CVD were the major causes of death accounting for approximately 50% of total mortality in Thai type 2 diabetic patients. Age, the presence of proteinuria and low HDL-C were independent risk factors for the development of CHD. The mortality from and the incidence of CHD in Thai type 2 diabetic patients are lower than those reported from Caucasian populations but the incidence of stroke appears to be higher. These findings need to be confirmed by a large-scale population-based study.

Association between circadian rhythm of blood pressure and glucose tolerance status in normotensive, non-diabetic subjects

AIMS To examine whether circadian rhythm of blood pressure (BP) is associated with glucose tolerance status in normotensive, non-diabetic subjects. METHODS A cross-sectional study recruited normotensive and non-diabetic subjects, aged 35-79 years. A 75 g oral glucose tolerance test (OGTT) and 24-h ambulatory blood pressure monitoring (24-h ABPM) were performed. RESULTS Among 31 impaired glucose tolerance (IGT) and 36 normal glucose tolerance (NGT) study subjects, the mean (+/-S.D.) diurnal-nocturnal differences of average systolic BP (SBP) were 7.1+/-6.9 and 9.9+/-6.2 mmHg, respectively (p=0.086). In a linear mixed-effects regression model, however, taking each measurement of BP as the outcome, nighttime reduction of SBP in the IGT group was 7.19 mmHg, which was significantly smaller compared to a reduction of 9.80 mmHg in the NGT group (p-value for IGT: nighttime interaction=0.0014). The prevalence of non-dipping BP pattern was 77.4% in the IGT group which was significantly higher than 52.8% of the NGT group (p=0.036). Logistic regression revealed a significant effect of IGT for predicting non-dipping pattern with an adjusted odds ratio of 3.71 (95% CI: 1.09, 12.66, p=0.029). CONCLUSIONS Among normotensive, non-diabetic subjects, the decreased nocturnal BP reduction was associated with impaired glucose tolerance status.

Contribution of skeletal muscle mass on sex differences in 2-hour plasma glucose levels after oral glucose load in Thai subjects with normal glucose tolerance

Women have higher 2-hour plasma glucose levels after oral glucose challenge than men. The smaller skeletal muscle mass in women may contribute to the higher postload glucose levels. The objective of this study was to test the hypothesis that the different amount of skeletal muscle mass between men and women contributed to sex difference in postload plasma glucose levels in subjects with normal glucose tolerance. Forty-seven Thai subjects with normal glucose tolerance, 23 women and 24 age- and body mass index-matched men, were studied. Body fat, abdominal fat, and appendages lean mass were measured by dual-energy x-ray absorptiometry. Skeletal muscle insulin sensitivity was determined by euglycemic-hyperinsulinemic clamp. First-phase insulin secretion and hepatic insulin sensitivity were determined from oral glucose tolerance data. beta-Cell function was estimated from the homeostasis model assessment of %B by the homeostasis model assessment 2 model. Correlation and linear regression analysis were performed to identify factors contributing to variances of postload 2-hour plasma glucose levels. This study showed that women had significantly higher 2-hour plasma glucose levels and smaller skeletal muscle mass than men. Measures of insulin secretion and insulin sensitivity were not different between men and women. Male sex (r = -0.360, P = .013) and appendages lean mass (r = -0.411, P = .004) were negatively correlated with 2-hour plasma glucose, whereas log 2-hour insulin (r = 0.571, P < .0001), total body fat (r = 0.348, P = .016), and log abdominal fat (r = 0.298, P = .042) were positively correlated with 2-hour plasma glucose. The correlation of 2-hour plasma glucose and sex disappeared after adjustment for appendages lean mass. By multivariate linear regression analysis, log 2-hour insulin (beta = 18.9, P < .0001), log 30-minute insulin (beta = -36.3, P = .001), appendages lean mass (beta = -1.0 x 10(-3), P = .018), and hepatic insulin sensitivity index (beta = -17.3, P = .041) explained 54.2% of the variance of 2-hour plasma glucose. In conclusion, the higher postload 2-hour plasma glucose levels in women was not sex specific but was in part a result of the smaller skeletal muscle mass. The early insulin secretion, hepatic insulin sensitivity, and skeletal muscle mass were the significant factors negatively predicting 2-hour postload plasma glucose levels in Thai subjects with normal glucose tolerance.

Glutamic acid decarboxylase antibodies in non-insulin-dependent diabetes patients with secondary sulfonylurea failure in Thailand

The objective of this study was to determine the frequency of glutamic acid decarboxylase antibody (GAD-Ab) in Thai non-insulin-dependent diabetes (NIDDM) patients who had secondary sulfonylurea failure. Sera were collected from 40 NIDDM patients, who had history of secondary failure to treatment with sulfonylurea, for analysis of fasting c-peptide and GAD-Ab. Both c-peptide and GAD-Ab were measured using radioimmunoassay method. Of 40 patients, ten (25.0%) were positive for GAD-Ab with a mean level of 59.9 U/ml (median 58.5, range 3.4-127). Patients with (GAD-Ab (+) had a significantly lower fasting c-peptide levels than those with GAD-Ab(-) albeit shorter duration of diabetes (0.21 +/- 0.19 (S.D.) versus 0.52 +/- 0.33 nmol/l; P = 0.003). Duration of treatment with sulfonylurea in patients with GAD-Ab (+) was also shorter (4.6 +/- 3.5 versus 10.4 +/- 5.5 years; P = 0.001). Age at onset of diabetes did not differ between these two groups. Among 40% of patients who had insulin deficiency (fasting c-peptide level < 0.33 nmol/1), GAD-Ab was present in half and these GAD-Ab(+) patients had significantly shorter duration of sulfonylurea treatment (3.3 +/- 2.3 versus 10.0 +/- 7.9 years; P = 0.018). In conclusion, the frequency of GAD-Ab in Thai NIDDM patients with secondary sulfonylurea failure in this study was 25%. Almost all GAD-Ab(+) patients had insulin deficiency and most had been initially treated with sulfonylurea for a few years before depending on insulin. This group of patients represents a slowly progressive type I or latent autoimmune diabetes in adult diabetic population.