Rise In TSH Concentration Research Articles

Relationship between serum thyrotropin and urine albumin excretion in euthyroid subjects with diabetes.

Microalbuminuria represents vascular and endothelial dysfunction. Thyroid hormones can influence urine albumin excretion as it exerts crucial effects on the kidney and on the vascular system. This study explores the relationship between serum thyrotropin and urine albumin excretion in euthyroid patients with diabetes. A total of 433 patients with type 1 or 2 diabetes were included in this retrospective cross-sectional study. Data included anthropometric measurements and biochemical parameters from diabetes clinic. Males with urine albumin creatinine ratio >2.5 and female's >3.5 mg/mmoL were considered to have microalbuminuria. 34.9% of the patients had microalbuminuria. Prevalence of microalbuminuria increased according to TSH quartiles (26.9, 34.6, 38.5 and 44.9%, P for trend = 0.02). In a fully adjusted logistic regression model, higher TSH concentrations were associated with high prevalence of microalbuminuria (adjusted odds ratio 2.06 [95% CI: 1.14-3.72]; P = 0.02), while comparing the highest with the lowest quartile of TSH. Multiple linear regression analysis showed an independent association between serum TSH and urine albumin creatinine ratio (β = 0.007, t = 2.03 and P = 0.04). The risk of having microalbuminuria was higher with rise in TSH concentration in patients with younger age (<65 years), raised body mass index (≥25 kg/m2), hypertension, type 2 diabetes and hyperlipidaemia and age was the most important determinant ( P for interaction = 0.02). Serum TSH even in the euthyroid range was positively associated with microalbuminuria in euthyroid patients with diabetes independent of traditional risk factors. This relationship was strongest in patients with components of the metabolic syndrome.

EFFECT OF PROLONGED ORAL ADMINISTRATION OF TRH ON PLASMA LEVELS OF THYROTROPHIN AND PROLACTIN IN NORMAL INDIVIDUALS AND IN PATIENTS WITH PRIMARY HYPOTHYROIDISM

Forty mg TRH/day was given orally for 3 weeks to 10 euthyroid women and 10 women with primary hypothyroidism on low replacement doses of thyroxine. Once weekly oral TRH was replaced by an iv TRH-test (0.4 mg) with measurement of serum concentration of TSH, prolactin (PRL), thyroxine (T4), triiodothyronine (T3) and cholesterol. In the normal group, mean serum T4 concentration increased after one week and remained elevated. Serum TSH concentration showed a slight tendency to decline. Maximal rise in TSH concentration after iv TRH (deltaTSH) fell from a mean of 4.0 ng/ml to 1.4 ng/ml within one week and stayed low. T3, cholesterol, PRL and deltaprl were normal and unchanged throughout. In the hypothyroid group T4, T3, cholesterol, PRL and deltaPRL were not influenced by the TRH administration. In 2 patients (with the highest serum T4 concentrations) serum TSH concentration was normal and resistant to iv TRH. Of the 8 patients with elevated TSH, basal level and deltaTSH did not change in 2 (with subnormal T4 levels and the highest TSH levels). In the other 6 (with intermediate T4 levels) basal TSH fell from a mean of 10.1 ng/ml to 4.2 ng/ml, and deltaTSH from 10.0 ng/ml to 3.3 ng/ml after three weeks. It is concluded that in addition to feed-back effect of thyroid hormones, the pituitary response to long-term administration of TRH is determined by other factors. Among these may be reduced pituitary TRH receptor capacity and the activity of the TSH producing cells.

The Acute Thyroidal Response to Iodized Oil in Severe Endemic Goiter

The acute changes in serum thyrotropin (TSH) triiodothyronine (T3) and thyroxine (T4), were measured in 14 subjects, 4 to 10 (mean = 6) days following intramuscular iodized oil injection. In 8 subjects with small or absent goiter there was a significant fall in T3 and a rise in TSH concentrations, suggesting an acute inhibitory effect of the iodine. In 6 subjects with large multinodular goiters there was a marked rise in both T3 and T4, and reduction in the elevated basal TSH. Biochemical hyperthyroidism occurred in 3 of these subjects. The acute thyroid hormone response to iodized oil, whether inhibitory or stimulatory in a particular subject, depends both on goiter size and on the serum concentration of TSH.