title: Forearm bone mineral density varies as a function of adiposity in inuit women 40-90 years of age during the vitamin D-synthesizing period.
abstract: Aging Inuit women are at increased risk for low vitamin D status due to habitation at higher latitudes, darker skin, and ongoing nutrition transition. Lower serum 25-hydroxyvitamin D (25[OH]D) concentration and higher risk of fracture have been separately reported in Inuit women, with particular relevance to postmenopausal women. We evaluated vitamin D status, forearm bone mineral density (fBMD), and nutrition in Inuit women ≥40 years. Women (n = 568) were randomly selected to participate in the 2007-2008 International Polar Year Inuit Health Survey from 36 Arctic communities. fBMD was measured using peripheral dual-energy X-ray absorptiometry. Dietary intakes were derived from 24 h recall and food-frequency questionnaires. Fasting serum 25(OH)D, parathyroid hormone, and osteocalcin (OC) were measured using a LIAISON(®) automated analyzer. The weighted prevalence of women having 25(OH)D concentration below 37.5, 50, and 75 nmol/L was 7.2 %, 17.6 %, and 48.6 %, respectively, with older women having better status. The dietary density of most nutrients increased with age, as did traditional food intake. fBMD was low in 3 (1.4 %) premenopausal (Z score < -2) and 107 (29.6 %) postmenopausal (T score < -1.5) women. Regression revealed that either weight, body mass index, or percent body fat significantly predicted fBMD in premenopausal women, in addition to age and OC in postmenopausal women. Women ≥50 years have higher vitamin D status and more nutrient-dense diets than women 40-49 years. While measures of adiposity predicted fBMD in all women, additional predictors after menopause included age and bone turnover.
authors.affiliation: School of Dietetics and Human Nutrition, McGill University, Macdonald Campus, Ste Anne de Bellevue, QC, Canada.
authors.forename: Jessy
authors.initials: J
authors.lastname: El Hayek
authors.forename: Amy
authors.initials: A
authors.lastname: Pronovost
authors.forename: Suzanne
authors.initials: S
authors.lastname: Morin
authors.forename: Grace
authors.initials: G
authors.lastname: Egeland
authors.forename: Hope
authors.initials: H
authors.lastname: Weiler
mesh_terms: D050154:Adiposity; D000328:Adult; D000368:Aged; D015519:Bone Density; D005260:Female; D005542:Forearm / Q000503:physiopathology*; D006801:Humans; D004930:Inuit; D008875:Middle Aged; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000208:ethnology
chemical_list: D014807:Vitamin D