EFFECT OF RECENT ALCOHOL INTAKE ON PARATHYROID-HORMONE AND MINERAL METABOLISM IN MEN

The mechanisms by which alcohol intake, particularly moderate alcohol intake, effects bone metabolism are poorly defined. We have examined t he relationship between mineral metabolism and recent self-reported al cohol intake (SRAI) across a wide range of such intakes in a series of 104 men aged 32 to 78 years of age in an outpatient setting. A mornin g nonfasting urine, serum specimen and recent SRAI were obtained from each subject. SRAI was reported as between 0 and 45 oz/week. SRAI corr elated positively with liver function tests, including serum bilirubin (r = 0.30, p = 0.002), alkaline phosphatase (r = 0.30, p = 0.004), an d aspartate aminotransferase (SGOT) (r = 0.29, p = 0.006). SRAI correl ated with serum calcium corrected for albumin (r = -0.39, p < 0.001), estradiol (r = 0.43, p < 0.001), and immunoreactive parathyroid hormon e (iPTH) (r = -0.51, p < 0.001), as well as urinary calcium (per 100 m g of creatinine) (r = 0.55, p < 0.001). We have arbitrarily divided th e participants into two groups on the basis of their reported alcohol intake. individuals in the first group had intakes ranging from none t o moderate intake (drank 8.4 oz or less of ethanol per week, equivalen t to an average of two drinks daily or less). Those in the second grou p had moderate or heavier intake, with >8.4 oz of ethanol intake/week. Mean serum iPTH was significantly greater in those in the first group (none to moderate), compared with the second group (moderate or heavi er) (56.0 +/- 3.4 and 39.9 +/- 2.0 pM/liter, respectively). Calcium co rrected for serum albumin was significantly greater in individuals in the first, compared with the second, group (9.23 +/- 0.05 vs. 8.88 +/- 0.07 mg/dl, respectively). In addition, urinary calcium (corrected pe r 100 mg of creatinine) was significantly lower in the former, compare d with the tatter (3.1 +/- 0.4 vs. 8.4 +/- 1.1 mg/100 mg of creatinine , respectively). Similarly, urinary excretion of collagen crosslinks ( corrected per 100 mg of creatinine) was significantly less in men in t he second group, compared with the first group (316 +/- 38 vs. 530 +/- 78 nM/100 mg of creatinine, respectively). Not surprisingly, a series of correlations between iPTH and age, 250-hydroxyvitamin D, and testo sterone were significant in individuals with none to moderate SRAI, bu t not moderate or heavier SRAI. Significant independent predictors of serum iPTH in the entire group of men were age (P = 0.215, p = 0.025), SRAI (beta = -0.281, p = 0.003), 250-hydroxyvitamin D (beta = -0.309, p = 0.002), and testosterone (beta = -184,p = 0.048). We have conclud ed that, in free-living men, alcohol intake >8.4 oz/week was associate d with decreased serum iPTH concentrations.