Vitamin D deficiency, secondary hyperparathyroidism and bone mineral density in Pakistani and Norwegians living in Oslo, Norway / Vitamin D-mangel, sekundær hyperparathyroidisme og bentetthet hos pakistanere og nordmenn bosatt i Oslo

Abstract

ENGLISH SUMMARYWe studied the prevalence of vitamin D deficiency and bone mineral density in Norwegian born and Pakistani born men and women living in Oslo. We measured 25-hydroxyvitamin D, iPTH and ionized calcium in serum and bone mineral density (BMD) at the forearm with single energy X-ray absorptiometry. 1386 persons born in Norway and 177 persons born in Pakistan participated. Among the Pakistani born 9% of the men and 21% of women were seriously vitamin D deficient (25(OH)D < 12.5 nmol/l). None of the Norwegian born had such low levels of vitamin D. While 86% of the Norwegians were vitamin D sufficient (25(OH)D ≥ 50 nmol/l), only 8% of Pakistani men and 10% of Pakistani women had a sufficient vitamin D status. The prevalence of secondary hyperparathyroidism was four times higher in Pakistani women and five times higher in Pakistani men compared to their Norwegian counterparts. Unadjusted bone mineral density was not different between the two ethnic groups, but in the multivariate analysis BMD was 0.020 g/cm 2 (95% CI: 0.007-0.033) higher in Pakistani men than in Norwegian men. We also found 5-8% higher bone mineral density in Pakistani men and women when we controlled for different skeletal size. While BMD was lower in Norwegian women with, compared to Norwegian women without, secondary hyperparathyroidsm (-0.027 g/cm 2 , p = 0.019), there was no difference in BMD between Pakistani women with and without secondary hyperparathyroidsm. INNLEDNINGDet er kjent at vitamin D er viktig for å oppnå tilstrekkelig kalsiumabsorpsjon i tarmen. De klassiske konsekvensene av alvorlig vitamin D-mangel er rakitt og osteomalasi, som skyldes at kalsium-og fosfatnivået i ekstracellulaervaesken (ECV) er utilstrekkelig til å mineralisere benvevet. Redusert kalsiumabsorpsjon i tarmen på grunn av vitamin D-mangel vil stimulere sekresjonen av parathyroidhormon (PTH) fra biskjold-