The influence of smoking habits on thyroid gland volume: an ultrasonic approach.

The effects of smoking habits on thyroid function, echo-texture (nodules and/or cysts) and thyroid gland volume were determined by using ultrasound and measuring serum Thyroxin (T4), Triiodothyronine (T3), Thyrotropin (TSH) and TPO antibodies (ab-TPO) in 189 healthy smokers and non-smokers, randomly selected (111 females and 78 males) among the employees of our hospital and their relatives. When the entire group of subjects was considered the mean ratio of thyroid gland volume/body weight was found to be significantly higher in male (P < 0.05) and female (P < 0.05) smokers compared with non-smokers. In female smokers, mean serum thyroid-stimulating hormone (TSH) was lower (P < 0.05) and the degree of smoking was positively correlated with the ratio of thyroid gland volume/body weight (P < 0.05). However, when the subjects with a family history of goitre in first degree relatives were excluded from our study (14 females and 9 males), no significant differences in mean ratio of thyroid volume/weight or TSH between the remaining smokers and non-smokers were detected. In both sexes, the correlation between the degree of smoking and thyroid volume, although positive, did not reach statistical significance. No difference in prevalence of abnormal echogenicity and echo-texture (nodules and cysts) between smokers and non-smokers was detected. It is concluded that smoking habits present a goitrogenic effect only in subjects with a family history of goitre but have no influence on thyroid gland texture.

Conicity index as a predictor of blood pressure levels, insulin and triglyceride concentrations of healthy premenopausal women.

Conicity index (C index), an index of abdominal obesity that was developed based on a model of geometric reasoning, proved to be a sensitive and better than the waist to hip ratio indicator of risk for hyperlipidemia in Western populations. To evaluate comparatively the C index and the Waist-to-Hip Ratio (WHR) as predictors of blood pressure levels, insulin and triglyceride concentrations, we performed a cross-sectional study on 280 healthy women, 18-24 year-old. C index was found to be within the expected range (0.95 to 1.73) and significantly correlated with WHR (r = 0.562, p = 0.0001) and body weight (r = 0.312, p = 0.0001). Additionally, C index correlated with fasting insulin levels (r = 0.13, p = 0.03), and systolic blood pressure (r = 0.14, p = 0.02). WHR correlated with fasting insulin levels (r = 0.12, p = 0.05), systolic blood pressure (r = 0.12, p = 0.13) and triglycerides (r = 0.22, p = 0.0006). C index and WHR are equally good, albeit weak, predictors of fasting insulin and blood pressure levels, while WHR proved to be a better than C index predictor of triglyceride concentrations in this population of healthy premenopausal Greek women. Further epidemiologic studies to comparatively evaluate the two indexes as predictors of risk for the development of metabolic disorders and cardiovascular disease in various populations are needed.

Outcome of percutaneous transluminal coronary angioplasty in patients with subclinical hypothyroidism.

To determine the outcomes of percutaneous transluminal angioplasty (PTCA) in patients with subclinical hypothyroidism and to compare them with those in euthyroid patients, we studied retrospectively 48 hypothyroid (4 overtly and 44 subclinically hypothyroid) and 122 euthyroid patients who had a PTCA in Boston's Beth Israel Hospital between 1984 and 1994. No significant differences were detected in bradycardia (relative risk, RR: 0.96), tachyarrhythmia (RR: 0.62), heart failure (RR: 2.27), hypotension (RR: 1.95), or bleeding (RR: 2.48) in the immediate postprocedure period between euthyroid and subclinically hypothyroid patients. There was a trend towards an increased incidence of chest pain (43.2 vs 27.5%, RR: 1.57, p = 0.084), dissection (50 vs 33%, RR: 1.51, p = 0.06) as an immediate, and reocclusion as an early (within 2 weeks) postprocedure complication (6.25 vs .9%, RR: 6.81, p = 0.08). However, chest pain accompanied by electrocardiographic changes was not significantly different between the two groups (20.5 vs 14.7%, RR: 1.4, p = 0.47). There was no difference in the number of procedures rated as successful (subclinically hypothyroid vs euthyroid: 90.2 vs 92.7%). Hospital charges, discharge destination, interval to next admission to the hospital, and in-hospital mortality were not different between the two groups. Subclinical hypothyroidism does not appear to be a risk factor for significant morbidity or increased mortality following PTCA. Prospective long-term studies with increased statistical power are needed to clarify whether there is an association between hypothyroidism and complications (especially chest pain, dissection, and/or reocclussion) in the early (2 weeks) and late (6 months) post-PTCA period.