Biomedical subjects

Wen-Yen Chien

Publications and source records attributed to Wen-Yen Chien.

4 recordsLinked to original sources

PubMed2005

Orlistat for obesity: benefits beyond weight loss.

Orlistat lowers lipids and improves insulin sensitivity, but its effect on other metabolic syndrome related parameters is not known. To assess its influence on adiponectin, high sensitive C-reactive protein (hs-CRP) and other metabolic syndrome related parameters, this study enrolled 106 participants in a weight-reduction program and categorized them into a group of 51 who had been treated with orlistat 360 mg/day for one year and a group of 55 age and sex and body mass index (BMI) matched controls. The orlistat group had greater changes in BMI, % body fat (% BF), waist circumference, and insulin resistance, hs-CRP, leptin and adiponectin levels after one year on the program than the controls. After adjusting for % BF and waist circumference, change of serum leptin and adiponectin levels remained significantly different. It was found that orlistat could effectively manage obesity related co-morbidities, especially insulin resistance and atherosclerosis risk. It decreases leptin and increases adiponectin independent of % BF and waist circumference. Therefore, orlistat appears to have anti-diabetic and anti-atherogenic properties and may help prevent metabolic syndrome in the overweight people.

Adult↗

PubMed2004

Bone mineral density in women receiving thyroxine suppressive therapy for differentiated thyroid carcinoma.

BACKGROUND AND PURPOSE: Most patients with well-differentiated thyroid carcinoma have an excellent prognosis and are likely to live long enough to be subjected to osteoporosis. The purpose of this study was to investigate the consequences of treatment with a supraphysiological dose of levothyroxine (l-T4) on bone mineral density (BMD) in Taiwanese women with differentiated thyroid cancer. METHODS: A total of 69 (44 premenopausal, 25 postmenopausal) Taiwanese women with differentiated thyroid cancer were included in this retrospective study. These patients were free of disease recurrence after initial near-total thyroidectomy and I-131 radioablation, and had undergone regular l-T4 suppressive therapy for more than 3 years (mean, 7.3 +/- 3.0 years; range, 3 to 15 years). The degree of thyroid-stimulating hormone (TSH) suppression was determined based on the mean TSH score for each patient which was determined by analysis of all available follow-up TSH data, where 1 = undetectable TSH (< 0.2 mIU/mL); 2 = subnormal TSH (0.2 to 0.39 mIU/mL); 3 = normal TSH (0.4 to 4.0 mIU/mL); and 4 = elevated TSH (> 4.0 mIU/mL). The patients were divided into a full TSH suppression group with a mean TSH score in the range 1.0 to 1.99, and a partial TSH suppression group with a mean TSH score in the range 2.0 to 2.99. BMD was measured by dual-energy X-ray absorptiometry at the lumbar spine, femoral neck, Ward's triangle and total hip. Comparisons between subgroups of patients and controls were performed by unpaired t test. Correlation between BMD and other clinical variables was assessed by Pearson's correlation analysis. RESULTS: Postmenopausal patients (aged 57.7 +/- 6.9 years) had significantly higher serum calcium levels and decreased BMD at all sites of the spine and hip as compared with premenopausal patients (aged 38.6 +/- 6.7 years) with similar BMI and duration of TSH suppression. Comparison of BMD between postmenopausal patients and BMI- and age-matched controls revealed that the patient group had decreased BMD at all sites of measurement, although this difference was not significant. This phenomenon was not observed in the premenopausal patients. Furthermore, when BMD was compared between patients categorized as having full and partial suppression of TSH, only patients with full suppression in the postmenopausal group showed a tendency to lower BMD. There was a strong correlation of BMD with age, BMI and serum calcium level. However, no correlation was found between BMD and degree of TSH suppression or duration of l-T4 suppression therapy. CONCLUSION: Women with differentiated thyroid cancer who had long-term (mean, 7.3 +/- 3.0 years) l-T4 therapy and suppressed TSH levels had no evidence of lower BMD. However, patients with full suppression in the postmenopausal group showed a tendency towards lower BMD. Therefore, careful monitoring of BMD in postmenopausal women during suppression therapy is mandatory.

Absorptiometry, Photon↗

PubMed2002

Serum leptin concentrations of patients with sequential thyroid function changes.

BACKGROUND: Leptin, a recently discovered protein produced in adipocytes, regulates body weight by suppressing food intake and/or increasing energy expenditure. Thyroid hormones, which increase the basal metabolic rate and thermogenesis, have been reported to be one of leptin's regulating factors because alternations in thyroid status might lead to compensatory changes in circulating leptin. OBJECTIVE: The aim of this study was to assess the influence of sequential changes in thyroid function on serum leptin levels. PATIENTS AND METHODS: The thyroid function status of 65 patients (55 women and 10 men, aged 40.6 +/- 15.2 years, mean +/- SD) with differentiated thyroid cancer who had received near-total thyroidectomy was studied before I-131 ablation therapy and after 2-4 and 6 months of levo-thyroxine suppressive therapy. Thirty-three (26 women, seven men; aged 41.0 +/- 10.4 years, mean +/- SD) of them were found to have become hypothyroid, then euthyroid and subsequently subclinically hyperthyroid. Their body mass index (BMI), body fat (%BF) by electrical bioimpedance, thyroid function and fasting serum leptin in these states were assessed and compared to those of 38 controls (30 women, eight men, aged 40.2 +/- 11.3 years, mean +/- SD). The controls had no past history or family history of thyroid diseases, and had the same range of BMI, between 20 and 30 kg/m2, as the patients. RESULTS: No difference in serum leptin levels was found between patients and controls with comparable age, sex, and BMI distribution in the euthyroid state. Using a repeated measures anova, tests of TSH, free T4 (FT4), BMI,%BF and leptin were performed on the 33 patients with sex as a grouping factor and thyroid state as a time factor. The sex difference for %BF and leptin proved to be statistically significant (P < 0.0001, and P = 0.0003, respectively). Serum leptin levels increased significantly from the hypothyroid to the subclinical hyperthyroid state (P < 0.0001) with a more pronounced increase found in females than in males (P = 0.03). Change of BMI during sequential thyroid function alterations was significant (P = 0.04) while change in %BF was not significant (P = 0.09). Pearson correlation analysis showed that serum leptin levels significantly correlated with BMI, %BF, FT4, and TSH (all P < 0.05). Using the generalized estimating equations, multivariate regression analysis revealed that FT4 was a statistically independent predictor for serum leptin (P < 0.0001). While other parameters were held constant, the mean serum leptin level increased by 1.47 units when serum FT4 was increased by one unit. CONCLUSION: In conclusion, our data indicate that circulating thyroid hormone plays a relevant role in regulating leptin metabolism independent of BMI and body fat.

Adult↗

PubMed2002

Relative impact of low-density lipoprotein-cholesterol concentration and insulin resistance on carotid wall thickening in nondiabetic, normotensive volunteers.

The relative effect of an increase in low-density lipoprotein-cholesterol (LDL-C) concentration, as compared with insulin resistance and its manifestations, on intimal medial thickening (IMT) of the common carotid artery was defined in 72 healthy men and women. Insulin-mediated glucose disposal was quantified by the insulin suppression tests, in which the height of the steady-state plasma glucose (SSPG) concentration during the last 30 minutes of a 180-minute infusion of octreotide, insulin, and glucose provides an estimate of insulin resistance. IMT was determined by high-resolution B-mode ultrasonography. Univariate analyses defined statistically significant correlation coefficients between IMT and LDL-C concentration (r =.25, P <.05), SSPG concentration (r =.32, P <.01), triglycerides (TG) (r =.25, P <.05), and high-density lipoprotein-cholesterol (HDL-C) (r = -.28, P <.05) concentrations (changes associated with insulin resistance) and ratio of waist-to-hip girth (r =.29, P <.05). When forward step-wise linear regression analysis was used, concentrations of SSPG, LDL-C and HDL-C all emerged as independent predictors of IMT (P <.05). Furthermore, the magnitude of their relationship to IMT values was comparable. These results provide evidence that insulin resistance is as significant a predictor of degree of atherogenesis (estimated by IMT) of the common carotid artery as a high LDL-C concentration.

Adult↗