RESUMEN
A positive correlation between Thyroid-Stimulating Hormone (TSH) and Body Mass Index (BMI) has been reported in many studies, but data on this topic remain controversial, especially when TSH values are in the normal range. Moreover, few studies have evaluated the co-existence of thyroid autoimmunity. This study investigated the role of thyroid autoimmunity in the interconnection between TSH, BMI, and waist circumference (WC) in euthyroid patients with overweight or obesity. We enrolled 902 patients (213 males; mean age ± SD: 45 ± 14 years; mean BMI ± SD: 35.8 ± 6.5 kg/m2), with normal serum TSH concentration; anti-thyroid autoantibodies (ATAs) were evaluated in 752 patients (186 males). Patients were divided into four BMI classes, based on WHO criteria, and the relationship between BMI, WC, and TSH was evaluated in the whole sample and compared to ATAs positivity, observed in 235 patients (44 males). No significant difference was found between TSH levels in the BMI classes. A statistically significant correlation between TSH and BMI was found only in ATAs-positive females (N = 191, Spearman rho: 0.149; p-value: 0.040). However, this finding was not confirmed when considering the WC. Our study shows a positive correlation only between TSH and BMI in obese women with positive ATAs, suggesting that in these patients, the high normal levels of TSH could be attributed to a mild thyroid failure with a possible worsening obesity-related effect, and both need a careful evaluation.
RESUMEN
AIMS: Stable genetic background makes individuals from the Mediterranean island of Sardinia ideal to define the predictive power of islet-related autoantibodies (IRAs): glutamic acid decarboxylase antibodies (GADA), tyrosine phosphatase-like antibodies (IA-2A), islet cell antibodies (ICA) to identify T1DM progressors. The aims of the present study were: (1) determination of IRAs reference limits in healthy non-diabetic Sardinian schoolchildren (SSc). (2) Predictive power evaluation of IRAs as single or combined determination to identify islet to identify T1DM progressors. METHODS: Between 1986 and 1994, 8448 SSc were tested for IRAs. All were followed up for 10 years. The predictive power of single or combination of IRAs was determined as hazard ratio (HR), sensitivity, specificity, area under the ROC curve, negative and positive predictive value (NPV, PPV). RESULTS: All 43 progressors to T1DM, but three showed at least one autoantibody positivity. HR for any single-autoantibody positivity was 55.3 times greater when compared to SSc negative for all IRAs. Any single autoantibody performed at least 64.9 % sensitivity with PPV always lower than 16 %. The best performing combination was ICA, plus IA-2A (showing 52.6 % sensitivity, 99.8 % specificity, 0.76 area under the ROC curve, 51.3 % PPV and 99.8 % NPV. CONCLUSIONS: Determination of IRAs reference limits in healthy SSc by standard statistical methods is crucial to establish the power of IRAs as progression markers to T1DM. Our data offer a solid rationale for future testing of ICA and IA-2A as routine laboratory markers to identify individuals at high risk of T1DM in the general population.
Asunto(s)
Autoanticuerpos/sangre , Diabetes Mellitus Tipo 1/diagnóstico , Islotes Pancreáticos/inmunología , Adolescente , Niño , Preescolar , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 1/epidemiología , Diabetes Mellitus Tipo 1/inmunología , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Glutamato Descarboxilasa/inmunología , Humanos , Italia/epidemiología , Masculino , Pronóstico , Proteínas Tirosina Fosfatasas/inmunología , Instituciones Académicas/estadística & datos numéricos , Sensibilidad y EspecificidadRESUMEN
The mechanisms deputed to energetic control have been selected by ancestral diets resulting from the nutrient disposal during the evolution. Discovery of the leptin and its downstream peptidergic pathways has increased our understanding of the physiological system that regulate food intake in the last decade. Hypothalamus plays a key role in the regulation of the peripheral and central signals of energy requirements. Insulin and leptin, that reflect the adipose status, are able to long term influence these circuits. Gut hormones acutely modulated the pathways, resulting in a stimulation effects by ghreline, or in a inhibition effects by PYY and oxintomoduline. Moreover, brain centres signal energy homeostasis by monoamine release and endocannabinoid system. This review discusses the network of neuronal and hormonal signals, which contribute to the energetic control.