Skin Color and Self-reported Sun Exposure Scores are Associated with Serum 25-Hydroxyvitamin D Concentrations in a Multi-ethnic Population Living in South Florida.

Aims: The aim was to investigate the association between serum 25-hydroxyvitamin D [25(OH)D], skin color and sun exposure score. Study Design: Cross-sectional. Place and Duration of Study: Florida International University, Robert Stempel College of Public Health and Social Work, Department of Dietetics and Nutrition, Miami, Florida from July 2012 to October 2012. Methodology: Seventy six adults, ages 18-36 years living in South Florida participated in the study. Skin color was quantified by a IMS Smart Probe 400 scanner and 25(OH)D was measured by ELISA. A sun exposure questionnaire was used to record the weekly sun exposure scores. A food frequency questionnaire was used to record daily vitamin D intake. Results: Multiple-linear regression analysis indicated that sun exposure, forearm skin color and vitamin D intake were significant predictors of 25(OH)D (P=.004, P=.003 and P=.021 respectively). This association held after controlling for covariates (B=.371, P=.027 for forearm, B=.031, P=.005 for total sun exposure and B=.689, P=.003 for vitamin D intake). Conclusion: Skin color, sun exposure along with vitamin D intake may be used as an indirect non-invasive tools to estimate 25(OH)D levels in healthy individuals in South Florida.

Use of Homeostatic Model Assessment Indexes for the Identification of Metabolic Syndrome and Insulin Resistance among Cuban-Americans: A Cross Sectional Study.

Aim: to determine cut off points for The Homeostatic Model Assessment Index 1 and 2 (HOMA-1 and HOMA-2) for identifying insulin resistance and metabolic syndrome among a Cuban-American population. Study Design: Cross sectional. Place and Duration of Study: Florida International University, Robert Stempel School of Public Health and Social Work, Department of Dietetics and Nutrition, Miami, FL from July 2010 to December 2011. Methodology: Subjects without diabetes residing in South Florida were enrolled (N=146, aged 37 to 83 years). The HOMA1-IR and HOMA2-IR 90th percentile in the healthy group (n=75) was used as the cut-off point for insulin resistance. A ROC curve was constructed to determine the cut-off point for metabolic syndrome. Results: HOMA1-IR was associated with BMI, central obesity, and triglycerides (P<0.05). HOMA2-IR was associated with BMI, central obesity, total cholesterol, HDL-cholesterol and LDL-cholesterol (P<0.05). The cut-off points for insulin resistance for HOMA-1 and HOMA-2 were >3.95 and >2.20 and for metabolic syndrome were >2.98 (63.4% sensitivity and 73.3% specificity) and >1.55 (60.6% sensitivity and 66.7% specificity), respectively. Conclusion: HOMA cut-off points may be used as a screening tool to identify insulin resistance and metabolic syndrome among Cuban-Americans living in South Florida.

Use of hemoglobin A1C to detect Haitian-Americans with undiagnosed Type 2 diabetes / Utilização de hemoglobina A1C no rastreamento de haitianos americanos com diabetes tipo 2 não diagnosticado

OBJECTIVE: To evaluate the validity of hemoglobin A1C (A1C) as a diagnostic tool for type 2 diabetes and to determine the most appropriate A1C cutoff point for diagnosis in a sample of Haitian-Americans. SUBJECTS AND METHODS: Subjects (n = 128) were recruited from Miami-Dade and Broward counties, FL. Receiver operating characteristics (ROC) analysis was run in order to measure sensitivity and specificity of A1C for detecting diabetes at different cutoff points. RESULTS: The area under the ROC curve was 0.86 using fasting plasma glucose ≥ 7.0 mmol/L as the gold standard. An A1C cutoff point of 6.26% had sensitivity of 80% and specificity of 74%, whereas an A1C cutoff point of 6.50% (recommended by the American Diabetes Association - ADA) had sensitivity of 73% and specificity of 89%. CONCLUSIONS: A1C is a reliable alternative to fasting plasma glucose in detecting diabetes in this sample of Haitian-Americans. A cutoff point of 6.26% was the optimum value to detect type 2 diabetes.

OBJETIVO: Avaliar a validade da hemoglobina A1C (A1C) como ferramenta para o diagnóstico de diabetes tipo 2 e determinar o ponto de corte mais apropriado para a A1C no diagnóstico de uma amostra de haitianos americanos. SUJEITOS E MÉTODOS: Os sujeitos (n = 128) foram recrutados dos condados de Miami-Dade e Broward na Flórida. A análise ROC (Receiver operating characteristics) foi feita de forma a medir a sensibilidade e especificidade de A1C para a detecção do diabetes em diferentes pontos de corte. RESULTADOS: A área sob a curva ROC foi 0,86 usando a glicemia de jejum ≥ 7,0 mmol/L como padrão-ouro. O ponto de corte de 6,26% para a A1C apresentou sensibilidade de 80% e especificidade de 74%, enquanto o ponto de corte de 6,50% (recomendado pela American Diabetes Association - ADA) apresentou uma sensibilidade de 73% e especificidade de 89%. CONCLUSÕES: A A1C foi uma alternativa confiável para a glicemia de jejum na detecção do diabetes nesta amostra de haitianos americanos. Um ponto de corte de 6,26% foi o valor ótimo para a detecção do diabetes tipo 2.