Serum leptin in overt and subclinical hypothyroidism: effect of levothyroxine treatment and relationship to menopausal status and body composition.

BACKGROUND: The relationship between thyroid status, including subclinical hypothyroidism (SH) and serum leptin is controversial or uncertain. Therefore we evaluated serum leptin in SH and overt hypothyroidism (OH) and determined the effects of levothyroxine (LT(4)) replacement on serum leptin in these disorders. METHODS: Serum leptin, thyrotropin (TSH), free thyroxine, insulin, glucose, and body composition parameters were compared in 55 SH, 20 OH, and 28 euthyroid (EU) pre- and postmenopausal women. In addition, the effect of LT(4) treatment on serum leptin in SH and OH was assessed. RESULTS: The mean +/- SD (median) serum leptin concentrations in the OH and SH groups were higher than in the EU group (35.1 +/- 27.2 [33.0] and 36.6 +/- 21.9 [30.6] ng/mL, respectively, vs. 23.2 +/- 19.3 [17.9] ng/mL, p = 0.011), but the difference was only significant in postmenopausal women. The body mass index (BMI), fat mass index (FMI), and the homeostasis model assessment-insulin resistance (HOMA-IR) index values were not different among these groups. In premenopausal women there was no correlation between leptin, BMI, or FMI and serum TSH levels (r(s) = 0.009, p = 0.474; r(s) = 0.043, p = 0.367; r(s) = 0.092, p = 0.232). In the postmenopausal women, the partial correlation coefficient between TSH and leptin was present, even when controlling for BMI (r(s) = 0.297, p = 0.042) and FMI (r(s) = 0.275, p = 0.050). LT(4) treatment was associated with a reduction of serum leptin concentrations in the OH group (p = 0.008). In SH group there were no differences between LT(4) replacement or no treatment, since a fall in serum leptin levels was detected in both SH subgroups, despite a more pronounced fall with LT(4) use. Treatment of the SH and OH groups with LT(4) did not influence HOMA-IR index or body composition. CONCLUSIONS: Serum leptin concentrations are elevated in postmenopausal women with SH or OH. A relationship between thyroid status and serum leptin is further supported by the fact that LT(4) treatment, to restore the EU status, reduced serum leptin levels in OH in the absence of significant effects on BMI. In women, hypothyroidism influences either leptin secretion or degradation and this effect is more pronounced in postmenopausal than in premenopausal women.

Alternative, age- and viral load-related routes of nelfinavir resistance in human immunodeficiency virus type 1-infected children receiving highly active antiretroviral therapy.

To assess prevalence of nelfinavir resistance mutations in children receiving highly active antiretroviral therapy, sequencing of protease gene from plasma of 53 human immunodeficiency virus-infected children was performed. The prevalence of L90M was similar to that of D30N. There was a significant correlation with a higher viral load and lower age and the occurrence of L90M. These findings suggest differential molecular age- and viral load-related routes for nelfinavir resistance.

Serological findings during a measles outbreak occurring in a population with high vaccine coverage

No periodo de marco/1991 a abril/1992, foram escolhidas 112 amostras sanguineas para a deteccao de anticorpos da classe IgM de casos de sarampo notificados a Divisao de Epidemiologia da Fundacao Municipal de Saude de Niteroi, Estado do Rio de Janeiro. A positividade ultrapassou 90 por cento para os especimens escolhidos entre o 5º e o 29º dia apos o inicio da doenca. A partir do 30º dia foi observado um declinio na deteccao de IgM, embora positividade tenha sido constatada ate noventa dias do inicio dos sintomas. Historia de vacinacao previa estava presente em 48,9 por cento destes pacientes. Dos 22 casos restantes, em 5 a infeccao era devido a outros agentes (rubeola: 4 casos, dengue: 1 caso). Estes resultados demonstram que a sensibilidade do teste empregado para confirmacao de casos suspeitos de sarampo e elevada mesmo em pacientes vacinados.