Prevalence of the metabolic syndrome, insulin resistance index, leptin and thyroid hormone levels in the general population of Merida (Venezuela).

The metabolic syndrome (MetSyn) is a significant risk factor for cardiovascular events, but scarce information exists about its frequency in Venezuela. In this cross-sectional study, we quantified the prevalence of the MetSyn in a probabilistic, stratified sample of 274 subjects aged > or =18 years from the Libertador district in Merida, Venezuela. Secondary outcomes were the measurement of thyroid hormones (free T4 and TSH), leptin levels, and insulin resistance index (HOMA2-IR). The frequency of MetSyn (percentage +/- 95% confidence interval) according to several diagnostic criteria was as follows: National Cholesterol Education Panel (NCEP, original): 27.4% (22.1-32.7); modified NCEP: 31.8% (26.3-37.3); International Diabetes Federation: 40.9% (35.1-46.7); Latin American Diabetes Association: 27% (21.7-32.3), and Venezuelan criteria: 31.8% (26.3-37.3). The MetSyn was more frequent in males than in females with most diagnostic criteria. The estimated prevalence of type 2 diabetes mellitus was 2.9% either according to the patients' self reports or to fasting glucose level found to be above 126 mg/dL. Abnormal HOMA2-IR index, free T4 and TSH (above the 95th percentile) were detected in 4.5%, 4.4% and 5.1% of the sample, respectively. Free T4 and TSH levels below the 5th percentile were detected in 4.4% and 4.7% of subjects respectively. These values are presented for comparisons with forthcoming studies in specific clinical populations. While studies are being conducted about the different definitions of the MetSyn in Venezuela, we recommend analyzing and publishing local research data with all the available criteria so as to allow comparisons with the results already reported in the literature.

Frequency of abnormal correlation between leptin and the body mass index during first and second generation antipsychotic drug treatment.

BACKGROUND: Leptin dysregulation has been implicated in the body weight gain and metabolic dysfunction observed with the second generation antipsychotic drugs (SGAD) olanzapine and clozapine. METHODS: This study quantified the frequency of subjects with abnormal correlation between leptin and the body mass index controlling for gender (defined as being out of the upper or lower 95% confidence interval in the regression line when combining each group with the drug-free subjects) after prolonged treatment with olanzapine (n=126), clozapine (n=62), first generation antiypsychotics (n=91), other SGAD (n=22), other psychotropic drugs (n=65) and drug-free subjects (n=229). RESULTS: None of the analysis was significant (p>0.05). In fact, in 17 out of 20 comparisons, the drug-free group had numerically higher frequencies of outliers than the corresponding treatment group. There were 28 outliers (4.7% of the total sample). In agreement with previous studies, cross-sectional analysis did not report gross alterations in serum leptin levels during olanzapine or clozapine administration. CONCLUSIONS: Longitudinal studies should focus on leptin regulation early on treatment, on the frequency of abnormal leptin receptor sensitivity and/or specific polymorphisms in the leptin allele and on several confounding factors in order to design personalized preventive and therapeutic measures.

Similar frequency of abnormal correlation between serum leptin levels and BMI before and after olanzapine treatment in schizophrenia.

Melkersson proposed leptin dysregulation as a factor in the olanzapine-induced metabolic dysfunction. Their suggestion was based on the absence of the expected positive correlation between serum leptin levels and the BMI, and the loss of the sex-dependent difference in leptin levels, which are higher in women. Although subsequent studies did not confirm that proposal, few of them assessed basal leptin levels and corrected for body fat percentage. Along with these variables, we added a precise definition of participants out of the expected positive correlation in a large sample of schizophrenia patients. Sixty patients (26 women and 34 men) with severe schizophrenia undergoing chronic hospitalization and conventional antipsychotic treatment were switched to olanzapine (10-20 mg/day). We assessed at baseline, and at weeks 8 and 16 of treatment, the percentage of participants with abnormal correlation (out of the 95% confidence interval in the regression line) between leptin levels and the BMI, and the correlation between leptin and insulin, glucose, the insulin resistance index, c-reactive protein (CRP) and treatment response. Leptin levels were higher in women than in men (P<0.01). The positive correlation between leptin levels, BMI and percentage of fat were preserved. After olanzapine, 3.8% of women and 2.9-5.8% of men were out the 95% confidence interval, and the proportion was similar at baseline. Glucose, insulin, the insulin resistance index and the CRP levels significantly increased after olanzapine. The impact of olanzapine on leptin regulation appears discrete and limited to a small number of participants. Additional studies must clarify the features that render them to metabolic dysregulation.

Abnormal correlation between serum leptin levels and body mass index may predict metabolic dysfunction irrespective of the psychopharmacological treatment.

In an earlier study, we found a similar frequency of individuals with an abnormal correlation between serum leptin levels and body mass index (BMI) (outliers above or below the 95% confidence interval in the regression line) during treatment with antipsychotic drugs (n=301), other psychotropic drugs (n=65), and drug-free individuals (n=229). In this secondary analysis, we compare the frequency of the metabolic syndrome (International Diabetes Federation), its constituting variables, obesity, (BMI>30 kg/m), leptin and insulin serum levels, and an insulin-resistance index (homeostatic model assessment-insulin resistance) in outliers, nonoutliers distributed in their original treatment groups, and all the nonoutliers controlled by age, sex, and BMI. We identified 28 outliers, 24 above and four below the 95% confidence interval limits. Nine individuals were under antipsychotic treatment, four under other drug treatment, and 15 were drug-free. The outliers had a significantly higher frequency of metabolic syndrome and obesity, and higher values of waist circumference, triglycerides, insulin, and blood diastolic pressure. The outliers in the correlation between leptin and BMI may represent a population at high risk of metabolic dysfunction, irrespective of the specific psychotropic drug treatment administered.

Prevalencia del síndrome metabólico, índice de insulino resistencia y niveles de leptina y hormona tiroidea en la población general de Mérida (Venezuela) / Prevalence of the metabolic syndrome, insulin resistance index, leptin and thyroid hormone levels in the general population of Mérida (Venezuela)

The metabolic syndrome (MetSyn) is a significant risk factor for cardiovascular events, but scarce information exists about its frequency in Venezuela. In this cross-sectional study, we quantified the prevalence of the MetSyn in a probabilistic, stratified sample of 274 subjects aged ³18 years from the Libertador district in Mérida, Venezuela. Secondary outcomes were the measurement of thyroid hormones (free T4 and TSH), leptin levels, and insulin resistance index (HOMA2-IR). The frequency of MetSyn (percentage ± 95% confidence interval) according to several diagnostic criteria was as follows: National Cholesterol Education Panel (NCEP, original): 27.4% (22.1-32.7); modified NCEP: 31.8% (26.3-37.3); International Diabetes Federation: 40.9% (35.1-46.7); Latin American Diabetes Association: 27% (21.7-32.3), and Venezuelan criteria: 31.8% (26.3-37.3). The MetSyn was more frequent in males than in females with most diagnostic criteria. The estimated prevalence of type 2 diabetes mellitus was 2.9% either according to the patients’ self reports or to fasting glucose level found to be above 126 mg/dL. Abnormal HOMA2-IR index, free T4 and TSH (above the 95th percentile) were detected in 4.5%, 4.4% and 5.1% of the sample, respectively. Free T4 and TSH levels below the 5th percentile were detected in 4.4% and 4.7% of subjects respectively. These values are presented for comparisons with forthcoming studies in specific clinical populations. While studies are being conducted about the different definitions of the MetSyn in Venezuela, we recommend analyzing and publishing local research data with all the available criteria so as to allow comparisons with the results already reported in the literature.

El síndrome metabólico (SM) es un factor de riesgo significativo en la ocurrencia de eventos cardiovasculares. Sin embargo, existe poca información sobre su frecuencia en Venezuela. En la presente investigación transversal, cuantificamos la prevalencia del SM es una muestra probabilística de 274 sujetos con edad mayor o igual a 18 años provenientes del municipio Libertador de la cuidad de Mérida, Venezuela. Como resultados secundarios, se cuantificaron los niveles de leptina, hormonas tiroideas (T4 libre y TSH), y el índice de resistencia a la insulina (HOMA2-RI). La frecuencia de SM (porcentaje ± intervalo de confianza del 95%) de acuerdo a varios criterios diagnósticos fue la siguiente: Panel para el Colesterol (original): 27,4% (22,1-32,7); Panel para el Colesterol (modificado): 31,8% (26,3-37,3); Federación Internacional de Diabetes: 40,9% (35,1-46,7); Asociación Latino-Americana de Diabetes: 27% (21,7- 32,3) y criterios Venezolanos: 31,8% (26,3-37,3). Al utilizar la mayoría de los criterios, el SM fue más frecuente en hombres que en mujeres. La prevalencia estimada de diabetes mellitus tipo 2 fue 2,9% tanto mediante el auto-reporte como mediante la detección de glicemia en ayunas > 126 mg/dL. Se detectaron niveles anormales (por encima del percentil 95) del índice HOMA2-IR, T4 libre y TSH en el 4,5%, 4,4% y 5,1% de la muestra respectivamente. Niveles de T4 y TSH por debajo del percentil 5 se detectaron en el 4,4% y 4,7% de sujetos respectivamente. Los valores del HOMA2-RI y hormonas tiroideas también se presentan con el fin de permitir comparaciones con futuros estudios en poblaciones clínicas específicas. Mientras se realizan estudios adicionales en Venezuela sobre las diversas definiciones del SM, recomendamos analizar y publicar los resultados científicos locales con todos los criterios disponibles con el fin de permitir la comparación con los estudios que ya están disponibles.