TSH and free thyroxine concentrations are associated with differing metabolic markers in euthyroid subjects.

OBJECTIVE: To examine the association between thyroid function and the components of the metabolic syndrome and insulin resistance in an Hispanic population. DESIGN: Cross-sectional study. METHODS: Subjects with no history of thyroid disease or diabetes were included. Thyroid function was stratified as euthyroid or subclinical hypothyroidism (SCH) status and subsequently by free thyroxine (FT(4)) and TSH tertiles. The association of the metabolic syndrome components (defined by 2004 Adult Treatment Panel III criteria) and insulin resistance with thyroid status, TSH, and FT(4) were examined. RESULTS: A total of 3148 subjects were analyzed. The prevalence of SCH was 8.3%. The prevalence of the metabolic syndrome was similar in euthyroid and SCH patients (31.6 vs 32.06%, P=0.89). Total cholesterol was higher in patients with SCH (5.51+/-1.19 vs 5.34+/-1.05 mmol/l, P<0.032). Serum TSH values showed a positive correlation (adjusted for age and sex) with total cholesterol, triglycerides, and waist circumference. In contrast, FT(4) showed a positive correlation with high-density lipoprotein cholesterol, and an inverse correlation with waist circumference, insulin, and HOMA-IR. CONCLUSION: SCH is not associated with an increased risk for the metabolic syndrome (as conceived as a diagnostic category defined by the National Cholesterol, Education Program, Adult Treatment Panel III criteria). Despite this, low thyroid function (even in the euthyroid state) predisposes to higher cholesterol, glucose, insulin, and HOMA-IR levels. The combined use of TSH and FT(4), compared with the assessment based on only FT(4), is a more convenient approach to evaluate the association between thyroid function and metabolic variables.

Nortriptyline-fluphenazine vs. carbamazepine in the symptomatic treatment of diabetic neuropathy

We compared the efficacy and tolerance of the combination of nortriptyline-fluphenazine (NF) vs. carbamazepine (CNZ) in the symptomatic therapy of patients with severe, distal, symmetrical, predominantly sensitive diabetic polyneuropathy (DPN). We followed a double blind, crossover, randomized and double placebo design. Sixteen patients with severe DPN participated in the study. Patients received either NF (1 tablet three times a day (tid)), for 2 weeks. After this, patients received placebos of both drugs (wash-out period), until symptoms returned to baseline levels (100 percent), then they were crossed over to receive the other comparing drug schedule. A visual analoque scale was used to evaluate the percent changes in pain and paresthesia. HBA1, fasting serum glucose, and safety tests were performed at 2- and 4-week intervals, respectively. Both therapies produced significant improvement of both pain and paresthesis. No statistically significant differences were observed between both therapies for either pain or paresthesia. No significant biochemical changes were observed with any of the two therapies. Side effects were mild and more frequent in the NF period. In this study no superiority of either drug schedule was demonstrated; therefore, the decision to use any of them should be made according to the associated pathology and potential side effects of each drug