RESUMEN
Morbid obesity is associated with a high rate of raised serum TSH associated with normal free thyroid hormones. The body repercussions of this thyroid abnormality, suggesting subclinical hypothyroidism, are still debated. In particular, it is unclear whether the raised serum TSH of obesity results in changes of circulating lipids typically observed in hypothyroidism. Aim of this study was to evaluate the impact of a raised serum TSH on the lipid profile in morbid-obese and non-obese patients. Serum TSH, FT4, FT3, Tg-Ab, TPO-Ab and lipids were measured in 55 morbid-obese (BMI > 40 kg/m(2)) and 55 non-obese (BMI < 30 kg/m(2)) patients with a raised serum TSH. Despite similar serum levels of TSH, FT4 and FT3, morbid-obese patients displayed significantly lower mean levels of total cholesterol (200.8 ± 35.6 vs. 226.9 ± 41.4 mg/dl, p < 0.001) and a significantly lower prevalence of hypercholesterolemia (50.9 vs. 72.7 %, p < 0.01) when compared with non-obese patients. Morbid-obese patients also had lower mean serum HDL cholesterol and higher serum triglycerides. The impact of a raised serum TSH on the lipid profile differs in morbid-obese compared to non-obese patients, suggesting that obese patients might not be truly hypothyroid. Measuring total cholesterol could be a helpful tool for deciding whether a morbid-obese patient with a raised serum TSH should be given levothyroxine treatment.
Asunto(s)
Lípidos/sangre , Obesidad Mórbida/sangre , Tirotropina/sangre , Adulto , Colesterol/sangre , Femenino , Humanos , Hipertrigliceridemia/sangre , Hipertrigliceridemia/complicaciones , Hipertrigliceridemia/epidemiología , Hipotiroidismo/sangre , Hipotiroidismo/complicaciones , Hipotiroidismo/epidemiología , Peso Corporal Ideal , Metabolismo de los Lípidos , Masculino , Persona de Mediana Edad , Obesidad Mórbida/complicaciones , Obesidad Mórbida/epidemiología , Sobrepeso/sangre , Sobrepeso/complicaciones , Sobrepeso/epidemiología , PrevalenciaRESUMEN
OBJECTIVE: Morbid obesity (body mass index (BMI)> or =40 kg/m(2)) is associated with thyroid function disturbances, with a high rate of subclinical hypothyroidism (SH) being the most consistently reported. We evaluated the circulating thyroid function parameters in morbid obese patients and related the results to the presence of circulating thyroid antibodies (Thyr-Ab). DESIGN AND METHODS: Morbid obese patients were consecutively enrolled (n=350). Two control groups were used: control group (CG)1, healthy normo-weight subjects (n=50); CG2, normo-weight patients with SH (n=56) matched for TSH with the obese patients with SH. Serum levels of free triiodothyronine (FT(3)), free thyroxine (FT(4)), TSH, antithyroglobulin antibodies, and antithyroperoxidase antibodies were measured in all patients. RESULTS: i) Compared with CG1, obese patients having thyroid function parameters in the normal range and negative Thyr-Ab showed significantly higher serum TSH and lower free thyroid hormones levels, but a similar FT(4)/FT(3) ratio; ii) SH was recorded in 13.7% obese patients; iii) compared with CG2, obese patients with untreated SH had a significantly lower rate of positive Thyr-Ab (32.1 vs 66.1%; P<0.005); iv) no gender prevalence was observed in SH obese patients with negative Thyr-Ab; and v) the comparison of the untreated SH patients (obese and normo-weight) with CG1 demonstrated that in SH obese subjects, unlike normo-weight SH patients, the FT(3) levels were significantly lower. This resulted in a normal FT(4)/FT(3) ratio in SH obese patients. CONCLUSION: Thyroid autoimmunity is not a major cause sustaining the high rate of SH in morbid obese patients. In these patients, the diagnosis of SH itself, as assessed by a raised TSH alone, appears questionable.
Asunto(s)
Hipotiroidismo , Obesidad Mórbida/sangre , Obesidad Mórbida/epidemiología , Tiroiditis Autoinmune , Tirotropina/sangre , Adulto , Autoanticuerpos/sangre , Biomarcadores/sangre , Peso Corporal , Femenino , Humanos , Hipotiroidismo/sangre , Hipotiroidismo/diagnóstico , Hipotiroidismo/epidemiología , Masculino , Persona de Mediana Edad , Peroxidasa/inmunología , Valor Predictivo de las Pruebas , Prevalencia , Tiroiditis Autoinmune/sangre , Tiroiditis Autoinmune/complicaciones , Tiroiditis Autoinmune/diagnóstico , Tiroxina/sangre , Triyodotironina/sangreRESUMEN
BACKGROUND: The metabolic syndrome is a cluster of cardiovascular risk factors (central obesity, hypertension, dyslipidemia, disturbance in glucose metabolism) associated with insulin-resistance. The cluster of risk factors defining the metabolic syndrome increases cardiovascular risk more than each single component. The aim of the present longitudinal study was to evaluate the relationship between weight loss and changes in insulin-resistance and in the prevalence of the metabolic syndrome 1-year after SAGB implantation. METHODS: 51 premenopausal severely obese women (mean age 35.2 +/- 8.8 years, BMI 43.3 +/- 6.9) were enrolled. As a control group, 51 premenopausal non-obese women (BMI < 30) were enrolled. All obese subjects underwent successful implantation of the SAGB via videolaparoscopy. In all subjects insulin-resistance was estimated by HOMA index and metabolic syndrome was defined according to the criteria of the European Group for the Study of Insulin Resistance. RESULTS: HOMA (4.2 +/- 2.0 vs 1.9 +/- 0.8, P < 0.001) and the prevalence of the metabolic syndrome (58.8% vs 7.8%, P < 0.001) were significantly higher in obese than non-obese women. 1 year after SAGB, BMI significantly decreased from 43.3 +/- 6.9 to 34.5 +/- 7.4 (P < 0.001). HOMA index showed a significant dramatic breakdown (4.2 +/- 2.0 vs 2.4 +/- 1.0, P < 0.001). The prevalence of the metabolic syndrome declined significantly (58.8% vs 21.6%, P < 0.001). CONCLUSION: Our study shows that in severely obese women, insulin-resistance and the prevalence of the metabolic syndrome significantly decrease 1 year after SAGB. Our findings indicate that SAGB could be a useful tool to reduce the global cardiovascular risk in severely obese people and to improve their long-term prognosis.