title: Prevalence of vitamin D deficiency and secondary hyperparathyroidism during winter in pre-menopausal Bangladeshi and Somali immigrant and ethnic Finnish women: associations with forearm bone mineral density.
abstract: Secondary hyperparathyroidism (SHPT) is one of the outcomes of vitamin D deficiency that negatively affects bone metabolism. We studied the ethnic differences in vitamin D status in Finland and its effect on serum intact parathyroid hormone (S-iPTH) concentration and bone traits. The study was done in the Helsinki area (60°N) during January-February 2008. A total of 143 healthy women (20-48 years of age) from two groups of immigrant women (Bangladeshi, n 34 and Somali, n 48), and a group of ethnic Finnish women (n 61) were studied in a cross-sectional setting. Serum concentrations of 25-hydroxyvitamin D (S-25OHD) and S-iPTH were measured. Peripheral quantitative computed tomography measurements were taken at 4 and 66 % of the forearm length. In all groups, the distribution of S-25OHD was shifted towards the lower limit of the normal range. A high prevalence of vitamin D insufficiency (S-25OHD < 50 nmol/l) was observed (89·6 %) in the Somali group. The prevalence of SHPT (S-iPTH>65 ng/l) was higher (79·1 %) in Somali women than in Finnish women (16 %). There was a significant association between S-25OHD and S-iPTH (r - 0·49, P < 0·001). Ethnicity and S-25OHD together explained 30 % of the variation in S-iPTH. The total bone mass at all sites of the forearm, fracture load and stress-strain index was higher (P < 0·001) in Bangladeshi and Finnish women than in Somali women. The high prevalence of hypovitaminosis D, SHPT and low bone status in Somali women indicates a higher risk of osteoporosis.
authors.affiliation: Calcium Research Unit, Department of Food and Environmental Sciences (Nutrition), University of Helsinki, PO Box 66, 00014 Helsinki, Finland.
authors.forename: Md Zahirul
authors.initials: MZ
authors.lastname: Islam
authors.forename: Heli T
authors.initials: HT
authors.lastname: Viljakainen
authors.forename: Merja U M
authors.initials: MU
authors.lastname: Kärkkäinen
authors.forename: Elisa
authors.initials: E
authors.lastname: Saarnio
authors.forename: Kalevi
authors.initials: K
authors.lastname: Laitinen
authors.forename: Christel
authors.initials: C
authors.lastname: Lamberg-Allardt
mesh_terms: D015652:25-Hydroxyvitamin D 2 / Q000097:blood; D000328:Adult; D001459:Bangladesh / Q000208:ethnology; D015519:Bone Density; D002112:Calcifediol / Q000097:blood; D003430:Cross-Sectional Studies; D054242:Emigrants and Immigrants; D005260:Female; D005387:Finland / Q000453:epidemiology; D005542:Forearm; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000097:blood / Q000453:epidemiology* / Q000208:ethnology / Q000209:etiology; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D017697:Premenopause; D015995:Prevalence; D012621:Seasons; D012720:Severity of Illness Index; D012998:Somalia / Q000208:ethnology; D014504:Urban Health / Q000208:ethnology; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology* / Q000208:ethnology / Q000503:physiopathology; D055815:Young Adult
chemical_list: C470125:PTH protein, human; D010281:Parathyroid Hormone; D015652:25-Hydroxyvitamin D 2; D002112:Calcifediol