Random capillary plasma glucose measurement in the screening of diabetes mellitus in high-risk subjects in Thailand.

To assess the usefulness of random capillary plasma glucose (RCPG) measurement in screening for diabetes mellitus in high-risk subjects, a RCPG measurement and a 75-g oral glucose tolerance test (OGTT) were performed in 684 women and 164 men, aged 16-76 years (mean+/-SD: 41.9+/-11.3 years). Risk factors included family history of diabetes in first degree relatives (53.8%), obesity (BMI > or =27 kg/m(2)) in 37.9%, dyslipidemia (78.4%), hypertension, i.e. BP > or =140/90 mmHg (28.5%), and history of gestational diabetes mellitus (16.6%). According to the 1997 ADA/1998 WHO Consultation criteria for a full OGTT, 118 cases (13.9%) were found to have diabetes. Each of 19 cases with RCPG > or =13.3 mmol/l had diabetes according to OGTT, 4.7% of 427 cases with RCPG<6.1 mmol/l had diabetes. Among 402 subjects with RCPG between 6.1 and <13.3 mmol/l, 19.7% were found to have diabetes. Thus, 446 (52.6%) of 848 subjects would have been saved from OGTT if RCPG was used as a screening test, in comparison to 33.1% if the cutpoints for RCPG (12.2 and 5.5 mmol/l) recommended by WHO Study Group (1985)/WHO Consultation (1998) were applied. Therefore, RCPG measurement is a useful screening test for the screening of diabetes mellitus in high-risk subjects.

Diagnostic criteria for diabetes mellitus and other categories of glucose intolerance: 1997 criteria by the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus (ADA), 1998 WHO consultation criteria, and 1985 WHO criteria. World Health Organization.

To compare 1997 ADA diagnostic criteria for diabetes mellitus and other categories of glucose intolerance/1998 WHO Consultation criteria versus 1985 WHO criteria, we analyzed data from a 75-g oral glucose tolerance test (OGTT) performed on 1051 high-risk subjects without medical history of diabetes at Diabetes Screening Clinic, Ramathibodi Hospital, Thailand. There were 372 males and 679 females, aged (mean +/- S.D.) = 50.3 +/- 12.55 years, BMI = 25.62 +/- 4.39 kg/m2. If fasting plasma glucose (FPG) was used as recently recommended then 54.1, 20.4, and 25.5% of cases were classified as normal, impaired fasting glucose (IFG), and diabetic, respectively. In diagnosing diabetes using a full OGTT based on the 1985 WHO criteria as the reference test, FPG > or = 7 mmol/l had a sensitivity of 57.7%, specificity of 97.4%, positive predictive value of 94.0%, and negative predictive value of 76.4%; 53.7% of subjects with IFG had 2-h plasma glucose > or = 11.1 mmol/l. The 1997 ADA/1998 WHO Consultation criteria and 1985 WHO criteria for a full OGTT yield similar overall results. FPG ( > or = 7 mmol/l) was not sensitive for diagnosing diabetes. Moreover, about half of the subjects with IFG were actually diabetic. Therefore, OGTT remains a valuable test in diagnosing diabetes and classifying various categories of glucose intolerance.

A de novo L330S point mutation in thyroid hormone receptor beta gene in a Thai female with resistance to thyroid hormone.

In the present study, we report a Thai female with a de novo mutation in thyroid hormone receptor-beta (TRbeta) gene causing resistance to thyroid hormone (RTH). The patient was a 19 year-old woman who presented with goiter for 1 year. Except for tachycardia she had no signs of thyrotoxicosis. Previously she was treated with propylthiouracil based on the diagnosis of thyrotoxicosis for 9 months and her goiter became more enlarged. The patient was the only child of the family. Her parents were alive and healthy, and did not have goiter or any other thyroid diseases. Physical examination revealed no sign of thyrotoxicosis. Her thyroid gland was diffusely enlarged with an estimated weight of 100 gm. Laboratory determinations revealed elevated free T4, T3 and nonsuppressed TSH levels. Exon 9 of the TRbeta gene was amplified by PCR and the DNA sequence was determined by dye terminator cycle sequencing. Heterozygous point mutation in which T was replaced by C was detected at position 1274 (TTG to TCG) corresponding to a leucine to serine substitution at codon 330. No mutation was found in the parents indicating that the mutation was de novo. The nucleotide change created a restriction site for Taq 1 restriction endonuclease and the mutation was confirmed by restriction fragments length polymorphism. The same nucleotide change has been reported in a family with RTH.

An evaluation of glycosylated hemoglobin measurement by a colorimetric method as a screening test for gestational diabetes mellitus.

To assess the potential value of glycosylated hemoglobin measurement (HbA1) in screening for gestational diabetes mellitus (GDM), HbA1 by a colorimetric method, plasma glucose level 1 hr after 50 g oral glucose loading, and 3-hr 100 g oral glucose tolerance test (3-hr OGTT) were performed in 334 pregnant women at Ramathibodi Hospital. These subjects carried high risk factors of GDM. Gestational ages varied from 24 to 38 wks. Twenty-four cases were diabetic (7.2%) by O'Sullivan and Mahan's criteria (1964). As a screening test to select subjects for 3-hr OGTT, plasma glucose level 1 hr after 50 g oral glucose load (plasma glucose level 7.8 mmol/L and above) has sensitivity: 87.50 per cent, specificity: 64.19 per cent. HbA1 level of 5.60 per cent (upper 95% confidence limit of the mean) and above yield sensitivity: 66.67 per cent, specificity: 61.29 per cent. Thus, glycosylated hemoglobin measurement as a screening test for GDM is not as effective as the conventional 50 g oral glucose loading test.

Predictive value of 1 hour 50 g oral glucose load screening test for gestational diabetes mellitus compared to 3 hour oral glucose tolerance test in high risk pregnant women.

A prospective study for detecting gestational diabetes mellitus was undertaken to evaluate the use of one hour plasma glucose level after 50 g glucose loading test (1-hr GLT) as compared to the traditional 3-hours 100 g oral glucose tolerance test (3-hr OGTT) in 396 high risk cases. Each patient, had 1-hr GLT and 3-hr OGTT performed in a separate week. Forty-two cases (10.6%) who had abnormal 3-hr OGTT were classified as gestational diabetes (GDM). One hundred and sixty cases (40.4%) had an abnormal 1-hr GLT (plasma glucose level > or = 140 mg/dl). Thirty-six of these 160 cases (22.5%) had an abnormal 3-hr OGTT. In 236 women (59.6%) that had normal 1-hr GLT (plasma glucose level < 140 mg/dl) only 6 cases (2.5%) had an abnormal 3-hr OGTT. If 1-hr plasma glucose level > or = 150 mg/dl was used as the cutoff point, 110 cases (27.8%) were found to have abnormal 1-hr GLT, and 35 of these 110 cases (31.8%) had an abnormal 3-hr OGTT. Seven of 286 women (2.4%) that had normal 1-hr GLT (plasma glucose level < 150 mg/dl) had an abnormal 3-hr OGTT. The sensitivity and specificity of the 1-hr GLT when abnormal 3-hr OGTT was used as gold standard for detecting GDM were 85.7% and 65% respectively (BS > or = 140 mg/dl). Whereas the sensitivity and specificity were 83.3% and 78.8% respectively when plasma glucose level > 150 mg/dl was used as the cut point.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased insulin secretion in subjects with impaired glucose tolerance.

In order to assess the relative roles of insulin deficiency and insulin resistance in the pathogenesis of impaired glucose tolerance (IGT), simultaneous measurement of serum immunoreactive insulin (IRI) and serum immunoreactive C-peptide (IRC) responses during 75 g oral glucose tolerance test were performed in 44 normal-weight adults with IGT (27 men, mean age +/- SEM = 46.1 +/- 1.9 year; 17 women, aged 49.1 +/- 3.3 year) and 44 control subjects (27 men, aged 45.5 +/- 2.1 year; 17 women, aged 47.9 +/- 3.0 year). Subjects with IGT had consistently higher 120-m IRI levels in comparison to corresponding age, sex, and BMI-matched control subjects, i.e. mean +/- SEM = 118.8 +/- 13.7 vs 57.0 +/- 6.9 microU/ml (male, P = 0.0002), and 116.3 +/- 11.8 vs 43.3 +/- 5.8 microU/ml (female, P = 0.0000). Similarly, 120-m IRC levels were higher in subjects with IGT, i.e. 2.12 +/- 0.26 vs 1.35 +/- 0.15 pmol/ml (male, P = 0.0262), and 3.13 +/- 1.01 vs 1.54 +/- 0.19 pmol/ml (female, P = 0.0080). Our findings indicate that increased insulin secretion is present in subjects with IGT, suggesting that insulin resistance is the predominant factor in the pathogenesis of IGT.

Impaired glucose tolerance in Thai adults: serum insulin profiles after a 75 gram oral glucose load.

Serum immunoreactive insulin (IRI) profiles after ingestion of a 75 g oral glucose load were measured in 150 Thai adults (50 men and 100 women, aged 15-71 years) with impaired glucose tolerance (IGT), and 133 control subjects (49 men and 84 women, aged 19-72 years). There were no significant differences in fasting and 30-minute serum IRI levels between subjects with IGT and corresponding age-, sex-, and body mass index (BMI)-matched controls, while subjects with IGT had consistently higher 120-minute serum IRI levels. Early serum insulin responses, as measured by ratio of increment in serum IRI level to that of plasma glucose level 30 minutes after glucose load (delta IRI 30/delta PG 30), were generally low or normal. However, when subjects with IGT are considered individually, there was marked heterogeneity in serum insulin responses, as judged by 120-minute serum IRI, delta IRI 30/delta PG 30, and ratio of sum of serum IRI levels during oral glucose tolerance test (0, 1/2, and 2 hour) to that of plasma glucose levels (sigma IRI/sigma PG). Most of the cases, i.e. 52, 76.7 and 69.3 per cent using previous criteria respectively, had normal insulin responses. We conclude that, 1) Thai adults with IGT generally have higher 120-minute serum IRI levels compared with corresponding age-, sex-, and BMI-matched controls, 2) early serum insulin responses as measured by delta IRI 30/delta PG 30 are generally low or normal, and 3) there is marked heterogeneity in serum insulin responses among these subjects.