RESUMEN
The annual inter- and intra-individual biological variation, including the circannual rhythmic variation, of the serum concentrations of magnesium and ionized calcium has been investigated in a group of 51 apparently healthy volunteers. Venous blood specimens were collected on intervals of once a month within a one-year period, using a standardized protocol. The inter-individual coefficients of variation were 5.12% for magnesium and 1.58% for ionized calcium. The medians of the intra-individual coefficients of variation were 1.93% for magnesium and 2.18% for ionized calcium. These data were used to determine the allowable imprecision, the allowable systematic error, the critical difference for significant change detection, and the usefulness of population reference values (index of individuality). Of the quantities studied, only the serum concentration of ionized calcium shows a significant annual rhythmic variation (amplitude 1.3%), although this result may be due to the between-run metrological variance, considering that the concentration of ionized calcium of the control material used during the study possesses a similar significant rhythmic variation.
Asunto(s)
Calcio/sangre , Magnesio/sangre , Adulto , Femenino , Humanos , Iones , Masculino , Persona de Mediana Edad , Modelos Teóricos , Valores de Referencia , Estaciones del Año , Factores de TiempoRESUMEN
The annual rhythmic variations of the serum concentrations of follitropin, lutropin, sex-hormone-binding globulin and testosterone, the ratio between the serum concentrations of testosterone and sex-hormone-binding globulin, and the salivary concentration of testosterone were investigated in a group of 20 apparently healthy men. Venous blood and salivary specimens were collected at 1-month intervals during 12 months. The annual rhythms were studied by using a periodic function resulting from the sum of three cosine functions with periods of 365, 182.5 and 121.66 days. For the salivary concentration of testosterone and for the ratio between the serum concentrations of testosterone and sex-hormone-binding globulin, only the cosine function with a period of 365 days was significant, and for the serum concentration of lutropin, only the cosine function with a period of 121.66 days was significant. Serum concentrations of follitropin, sex-hormone-binding globulin and testosterone were significantly affected by 365 and 121.66 rhythmic components. The salivary concentration of testosterone and the serum concentration of follitropin are the quantities with the greatest annual rhythmic variation of those studied.
Asunto(s)
Hormona Folículo Estimulante/sangre , Hormona Luteinizante/sangre , Periodicidad , Globulina de Unión a Hormona Sexual/análisis , Testosterona/metabolismo , Adulto , Europa (Continente) , Humanos , Masculino , Persona de Mediana Edad , Saliva/química , Factores de TiempoRESUMEN
The circadian rhythmic variations of the serum concentrations of follitropin, lutropin, sex-hormone-binding globulin and testosterone, the ratio between the serum concentrations of testosterone and sex-hormone-binding globulin, and the salivary concentration of testosterone were investigated in a group of 13 apparently healthy men. Venous blood and salivary specimens were collected at 4-h intervals over a 24-h period. The circadian rhythms were studied by using a periodic function resulting from the sum of two cosine functions with periods of 24 and 12 h. The serum concentrations of follitropin and lutropin showed no significant rhythmic variations. For the salivary concentration of testosterone and for the ratio between the serum concentrations of testosterone and sex-hormone-binding globulin, only the cosine function with a period of 24 h was significant. Serum concentrations of sex-hormone binding globulin and testosterone were significantly affected by 24- and 12-h rhythmic components. Of the quantities studied, the salivary concentration of testosterone showed the greatest daily rhythmic variation (28.8% of the mean estimated over rhythm).
Asunto(s)
Ritmo Circadiano , Hormona Folículo Estimulante/fisiología , Hormona Luteinizante/fisiología , Globulina de Unión a Hormona Sexual/fisiología , Testosterona/fisiología , Adulto , Humanos , Masculino , Valores de Referencia , Saliva/químicaRESUMEN
The within-subject and between-subject biological variation of the serum concentrations of follitropin, lutropin, sex-hormone-binding globulin, and testosterone; the ratio between the serum concentrations of testosterone and sex-hormone-binding globulin; and the concentration of testosterone in saliva have been studied in a group of 20 men during 12 months. The between-subject coefficients of variation (CVs) were 36.0% for follitropin, 37.0% for lutropin, 42.7% for sex-hormone-binding globulin, 21.3% for testosterone in serum, 28.8% for testosterone in saliva, and 51.6% for the ratio between serum concentrations of testosterone and sex-hormone-binding globulin. The medians of the within-subject CVs for the respective analyses and ratio were 17.3%, 24.0%, 12.1%, 10.9%, 17.3%, and 9.4%. These data were used to calculate the desirable imprecision, the critical difference for significant change detection, and the index of individuality.