Osteocalcin levels in a healthy population of western Mexico and comparison with populations from around the world. / Niveles de referencia de osteocalcina en población sana de México.

Introduction: Osteocalcin has been shown to have an inverse relationship with blood glucose, insulin resistance and adiposity. Objective: To determine osteocalcin normal serum concentration in Mexican healthy adults and compare it with values reported in other populations. Method: Carboxylated and undercarboxylated osteocalcin serum concentrations were determined in 100 healthy adults by means of enzyme immunoassay; osteocalcin total concentration was calculated. A descriptive comparison was made with other populations' values reported in the literature. Results: Carboxylated and undercarboxylated osteocalcin median concentrations were 3.22 ng/mL and 1.61 ng/mL, respectively. Mean total osteocalcin was 7.40 ± 5.11 ng/mL. There was no significant difference between the osteocalcin values in our population and those of populations where similar quantification methods to ours were used. Conclusion: Osteocalcin total serum concentration mean in the analyzed population was 7.40 ng/mL. There are subtle variations between populations that are attributable to genetic and population factors; however, the quantification method was the only variable that was shown to significantly influence on osteocalcin levels in healthy populations.

Introducción: Se ha demostrado que la osteocalcina tiene una relación inversa con la glucemia, resistencia a la insulina y adiposidad. Objetivo: Determinar la concentración sérica normal de osteocalcina en adultos sanos mexicanos y compararlos con los reportados en otras poblaciones. Método: Se determinó la concentración sérica de osteocalcina carboxilada y pobremente carboxilada en 100 adultos sanos mediante inmunoensayo enzimático; se calculó la concentración de osteocalcina total. Se hizo una comparación descriptiva con valores de otras poblaciones reportadas en la literatura. Resultados: Las medianas de las concentraciones de osteocalcina carboxilada y pobremente carboxilada fueron 3.22 ng/mL y 1.61 ng/mL, respectivamente; la media de osteocalcina total fue 7.40 ± 5.11 ng/mL. No hubo diferencia significativa entre los valores de osteocalcina total en nuestra población y los de poblaciones en las que se utilizaron métodos de cuantificación similares al nuestro. Conclusión: La concentración sérica promedio de osteocalcina total en la población analizada fue de 7.40 ng/mL. Las variaciones sutiles entre poblaciones son atribuibles a factores genéticos y poblacionales, sin embargo, el método de cuantificación fue el único que se comprobó influye significativamente en los niveles de osteocalcina en poblaciones sanas.

A cut-point value of uncarboxylated to carboxylated index is associated with glycemic status markers in type 2 diabetes.

BACKGROUND: The uncarboxylated osteocalcin (ucOC) has been described as a regulator of glucose metabolism in mice, and it is decreased in human type 2 diabetes mellitus (T2D). Although inversely correlated with serum glucose, insulin, and glycated hemoglobin, it is unclear if ucOC decrement is caused by diabetes or plays a role in the pathogenesis and/or progression of the disease. Whatever the case may be, diabetes affects osteoblast gene expression, and possibly the proportion of ucOC over carboxylated OC (cOC). The association of ucOC/cOC index with glycemic status markers in patients with T2D has not been described before. OBJECTIVE: The objective of this study was to assess the ucOC/cOC index and its relationship with glycemic status markers in patients with T2D. METHODS: The ucOC/cOC index was determined by the quotient of ucOC and cOC serum levels in 80 T2D patients and 160 healthy subjects. The relationship between the ucOC/cOC index and glycemic status markers was evaluated. RESULTS: The ucOC/cOC index was low and negatively correlated to fasting plasma glucose and homeostasis assessment-insulin resistance model in T2D patients. The odds ratio for T2D patients with an ucOC/cOC index below the cut-point obtained by receiver operating characteristic analysis was 12.64 (confidence interval, 5.75-27.77; P < 0.001). CONCLUSIONS: A value of ucOC/cOC index less than 0.3 is associated with markers of poor metabolic control in patients with T2D.