Effect of maternal hyperthyroidism during late pregnancy on the risk of neonatal low birth weight.

OBJECTIVE: Hyperthyroidism in pregnancy occurs with a prevalence of 0.05--0.2% and has been shown to affect neonatal outcomes. Fetal weight increases markedly during the third trimester of pregnancy. This retrospective study was performed to examine the effect of maternal hyperthyroidism during late pregnancy on neonatal birth weight (NBW). DESIGN: Medical and obstetric records of 293 pregnant women with present and past history of hyperthyroidism were retrospectively reviewed. PATIENTS: There were 188 records of 181 patients with adequate data for inclusion in the analysis. The patients were divided into two groups according to the maternal thyroid function during the third trimester of pregnancy: hyperthyroidism (HT; 35 cases) and euthyroidism (ET; 153 cases). MEASUREMENTS: Maternal thyroid function tests were periodically evaluated before and during the third trimester of pregnancy. Neonatal thyroid function tests and birth weight of the newborn infants were also assessed. RESULTS: There was no significant difference of maternal age between HT and ET groups mean +/- SD (27.6 +/- 5.5 vs. 29.2 +/- 5.4 years). The NBW of the HT group was not significantly different from that of the ET group (2880 +/- 590 vs. 3019 +/- 426 g). However, the prevalence of infants with low birth weight (LBW) defined as NBW of lower than 2500 g in HT group was 22.9% which was significantly higher than the 9.8% in the ET group (P = 0.039, OR = 2.7, 95%CI = 1.1--7.1) and 9.7% of infants born to healthy mothers at Siriraj Hospital (control group) between 1991 and 1995 (P = 0.01, OR = 2.7, 95%CI = 1.3--6.1). The 90% CI for the true difference between the prevalence of LBW infants born to ET and HT mothers was 0.7--25.4. There was no significant difference in the prevalence of LBW infants in ET and control groups. Multiple logistic regression analyses showed that maternal hyperthyroidism during the third trimester of pregnancy was an independent factor associated with increased prevalence of LBW infants (P = 0.037, OR = 4.1, 95%CI = 1.1--15.0). CONCLUSIONS: Maternal hyperthyroidism during the third trimester of pregnancy independently increases the risk of low birth weight by 4.1-fold. Appropriate management of hyperthyroidism throughout pregnancy is essential in the prevention of this undesirable neonatal outcome.

Efficacy of single daily dosage of methimazole vs. propylthiouracil in the induction of euthyroidism.

OBJECTIVE: Previous studies of the treatment of hyperthyroidism with a single daily dose of antithyroid drugs have demonstrated a favourable result with methimazole (MMI). However, the efficacy of a single daily dose of propylthiouracil (PTU) was inconsistent. The present prospective randomized study was conducted to compare the efficacy of a single daily dose of MMI and PTU in the induction of euthyroidism in patients with Graves' disease. SUBJECTS: Seventy-one patients with newly diagnosed Graves' disease were studied. METHODS AND MEASUREMENTS: Patients were randomized to two groups to receive once daily dose of either 15 mg MMI or 150 mg PTU for 12 weeks. The therapeutic efficacy was determined biochemically by serum total T3, total T4 and TSH levels at baseline and at 4, 8 and 12 weeks during the study period. RESULTS: There was no significant difference in baseline characteristics. Serum total T3 levels of the MMI group were significantly lower than those of the PTU group after four weeks of the treatment (3.54 +/- 0.72 vs. 5.49 +/- 2.74 nmol/l, P < 0.05) through the end of the study (2.22 +/- 1.42 vs. 4.30 +/- 1.78 nmol/l, P < 0.05). The changes in serum total T4 levels occurred in the same direction as serum total T3 levels but a significant difference was observed only after eight weeks of the treatment (MMI vs. PTU; 101.67 +/- 54.05 vs. 176.32 +/- 66.92 nmol/l, P < 0.05). At the end of the study, more patients in the MMI group had both serum total T3 and T4 levels less than the upper limit of the normal range compared to the PTU group (77.1% vs. 19.4%). Hypothyroidism was observed in 31.4% of the patients in the MMI group but not in the PTU group. CONCLUSIONS: During 12-weeks' treatment of Graves' hyperthyroidism, a single daily dose of 15 mg of MMI was much more effective in the induction of euthyroidism than a single daily dose of 150 mg of PTU. Once daily regimen of MMI not only decreased serum T3 and T4 levels more rapidly but also induced euthyroidism four times more effectively than did the once daily regimen of PTU. In the doses used in this study, MMI is preferable to PTU when a once-daily regimen of antithyroid drug is considered for the treatment of hyperthyroidism.

Efficacy of using basal plasma adrenocorticotropic hormone-radioimmunoassay (ACTH-RIA) level in the identification of the cause of Cushing's syndrome.

Basal (8.00 a.m.) plasma ACTH-radioimmunoassay (ACTH-RIA) levels were studied in 32 cases of endogenous Cushing's syndrome (17 Cushing's disease, 13 adrenocortical tumors, and 2 ectopic ACTH syndrome) and 11 normal volunteers. There were overlaps in the ranges of plasma ACTH-RIA levels among patients with Cushing's disease, adrenocortical tumors, and normal volunteers but not ectopic ACTH syndrome. By using different plasma ACTH-RIA levels as cut-off points in differentiating ACTH-dependent from ACTH-independent Cushing's syndrome, the level of 30 pg/ml had the highest diagnostic efficacy with a 94.7 per cent sensitivity, a 84.6 per cent specificity and a 90.6 per cent diagnostic accuracy.

Factors associated with diabetic foot ulceration in Thailand: a case-control study.

A case-control study was conducted to determine factors involved in foot ulceration in Thai non-insulin-dependent (Type 2) diabetic patients. Fifty-five patients with foot ulcers (42 females and 13 males) and 110 patients without foot ulcers (83 females and 27 males) were evaluated for 26 factors possibly associated with foot ulceration. The results showed that diabetic patients with foot ulcers had significantly lower diabetic knowledge and foot-care practice scores; poorer glycaemic control, renal function, and visual function, and higher prevalence of retinopathy and peripheral neuropathy than diabetic patients without foot ulcers, whereas there were no differences in peripheral vascular status between both groups, each having a low prevalence. Multiple logistic regression analyses indicated that the risk of developing foot ulcers was associated with only three factors which were peripheral nerve status as determined by somatosensory evoked potentials (OR = 1.67; 95% CI 0.31 -8.97), visual acuity (OR = 0.223 per unit decrease in decimal visual acuity; 95% CI = 0.005, 0.39) and fasting plasma glucose level (OR = 1.01 per mmol l-1 increase; 95% CI = 1.00, 1.02). We conclude that peripheral neuropathy, visual impairment, and poor glycaemic control, but not peripheral vascular insufficiency, are the major independent risk factors associated with foot ulceration in Thai diabetic patients.

Nocturnal 8 mg dexamethasone suppression test: a practical and accurate test for identification of the cause of endogenous Cushing's syndrome.

The efficacy of a nocturnal 8 mg dexamethasone suppression test (nocturnal DST) was compared with that of the standard high-dose dexamethasone suppression test (standard DST) in identifying the cause of endogenous Cushing's syndrome in 10 proven cases with Cushing's disease, 20 with adrenal tumours, and one with ectopic ACTH syndrome. The nocturnal test compared serum cortisol concentration at 8 am before and after administration of a single dose of 8 mg dexamethasone at 11 pm. Suppression of serum cortisol level to < 50% of the baseline value indicated a diagnosis of Cushing's disease, while a lack of suppression below that limit indicated one of the other two causes of Cushing's syndrome: glucocorticoid-secreting adrenal tumour or ectopic ACTH syndrome. The nocturnal DST had a sensitivity of 90%, a specificity of 100%, an accuracy of 96.8%, a positive predictive value of 100%, and a negative predictive value of 95.5%. These values are comparable to the efficacy of the standard DST in distinguishing Cushing's disease from glucocorticoid-secreting adrenocortical tumour or ectopic ACTH syndrome. Furthermore, this rapid test does not require hospitalisation or urine collection like the standard DST. The nocturnal 8 mg dexamethasone suppression test is practical, fairly reliable, and an effective alternative with which to identify the cause of endogenous Cushing's syndrome.

Effects of alpha-glucosidase inhibitor (acarbose) combined with sulfonylurea or sulfonylurea and metformin in treatment of non-insulin-dependent diabetes mellitus.

The effects of alpha-glucosidase inhibitor (acarbose) were studied in 36 patients with non-insulin-dependent diabetes mellitus (NIDDM), aged 34-67 years with a mean duration of diabetes of 8.8 +/- 0.9 years. They were poorly controlled with diet plus sulfonylurea alone or plus sulfonylurea combined with metformin drugs. Acarbose, 100 mg three times daily, was additionally given to these patients for six months. Results showed small but significant decreases (P < 0.001) in postprandial blood glucose level. Glycosylated hemoglobin level was lowered significantly (P < 0.001) and was normalised (level of < 8%) in 17 per cent of the patients. Fasting serum triglycerides level decreased significantly (P < 0.01), whereas, no significant changes in serum total cholesterol and HDL cholesterol levels were seen. Body weight also decreased significantly (P < 0.001) at the end of acarbose trial. Flatulence was the major side effect of acarbose found in 42 per cent of the patients but it was well-tolerated and may be transient and self-limited. We concluded that the addition of acarbose to the therapeutic regimens of diet therapy plus sulfonylurea or plus sulfonylurea combined with metformin drugs led to significant improvement of glycemic control. Acarbose may be a safe and valuable adjunct to diet and sulfonylurea and metformin treatments in obese, poorly-controlled patients with NIDDM.