TY - JOUR
T1 - Predictors and relationships of serum 25 hydroxyvitamin D concentration with bone turnover markers, bone mineral density, and vitamin D receptor genotype in Emirati women
AU - Saadi, Hussein F.
AU - Nagelkerke, Nicolaas
AU - Benedict, Sheela
AU - Qazaq, Hussein S.
AU - Zilahi, Erica
AU - Mohamadiyeh, Mohammad K.
AU - Al-Suhaili, Abdulrahim I.
N1 - Funding Information:
This study was supported by research grants from Sheikh Hamdan Bin Rashid Al Maktoum Award for Medical Sciences and the Faculty of Medicine and Health Sciences, UAE University. We thank Mr. Akram Mohammad, Mr. Javed Yasin, Mr. Awad Al Essa, and Mr. Mohammad El-Haj for their technical assistance. We are grateful for Professors M. Gary Nicholls and Abdu Adem for reviewing the manuscript, and for Dr. Bachar Afandi for his help in recruitment.
PY - 2006/11
Y1 - 2006/11
N2 - Objectives: To determine factors influencing serum 25 hydroxyvitamin D (25OHD) concentration and relationships between serum 25OHD concentration, bone turnover markers, bone mineral density (BMD), and vitamin D receptor (VDR) genotype in Emirati women. Methods: Serum 25OHD, parathyroid hormone (PTH), osteocalcin (OC), vitamin D binding protein (VDBP), and urinary deoxypyrdinoline (UDPD) concentrations and VDR genotype were determined in Emirati women volunteers who were participating in a study aiming at establishing a reference database for BMD. Results: Serum 25OHD concentration in the 259 women volunteers was 25.3 ± 10.8 nmol/l (mean ± SD), and all had vitamin D deficiency (25OHD <80 nmol/l). Mean serum 25OHD was highest in April (29.2 ± 13.0 nmol/l), which marks the end of the short and cooler winter season, and lowest in August (18.2 ± 5.9 nmol/l). No significant difference in 25OHD concentration was noted among Emirati women wearing different dress styles, but the mean serum 25OHD was significantly lower in comparison with non-Arab Caucasian women volunteers who dressed in a Western style (P < 0.001). Serum 25OHD correlated positively with age (r = 0.2), number of pregnancies (r = 0.16), dietary vitamin D intake (r = 0.15), serum calcium (r = 0.14), phosphorus (r = 0.14), VDBP (r = 0.15), and urinary calcium/creatinine (r = 0.2), and inversely with PTH (r = -0.22), OC (r = -0.13), and UDPD/creatinine (r = -0.15); P < 0.05 for all correlations. Multiple linear regression analysis showed that age, dietary vitamin D intake, multivitamin intake, and cooler season were independent positive predictors of serum 25OHD concentration (R2 = 0.18). The frequencies of VDR genotypes were 36% GG, 44.1% AG, and 19.9% AA. Allele frequencies were 58% for G allele and 42% for A allele and were in Hardy-Weinberg equilibrium (×2 = 1.44; P > 0.1). There was no statistically significant influence of VDR genotype on bone turnover or BMD. Conclusions: Vitamin D deficiency is highly prevalent in Emirati women and appears largely attributable to insufficient sunlight exposure. It is associated with increased bone turnover. VDR genotype does not appear to influence bone turnover markers or BMD in Emirati women.
AB - Objectives: To determine factors influencing serum 25 hydroxyvitamin D (25OHD) concentration and relationships between serum 25OHD concentration, bone turnover markers, bone mineral density (BMD), and vitamin D receptor (VDR) genotype in Emirati women. Methods: Serum 25OHD, parathyroid hormone (PTH), osteocalcin (OC), vitamin D binding protein (VDBP), and urinary deoxypyrdinoline (UDPD) concentrations and VDR genotype were determined in Emirati women volunteers who were participating in a study aiming at establishing a reference database for BMD. Results: Serum 25OHD concentration in the 259 women volunteers was 25.3 ± 10.8 nmol/l (mean ± SD), and all had vitamin D deficiency (25OHD <80 nmol/l). Mean serum 25OHD was highest in April (29.2 ± 13.0 nmol/l), which marks the end of the short and cooler winter season, and lowest in August (18.2 ± 5.9 nmol/l). No significant difference in 25OHD concentration was noted among Emirati women wearing different dress styles, but the mean serum 25OHD was significantly lower in comparison with non-Arab Caucasian women volunteers who dressed in a Western style (P < 0.001). Serum 25OHD correlated positively with age (r = 0.2), number of pregnancies (r = 0.16), dietary vitamin D intake (r = 0.15), serum calcium (r = 0.14), phosphorus (r = 0.14), VDBP (r = 0.15), and urinary calcium/creatinine (r = 0.2), and inversely with PTH (r = -0.22), OC (r = -0.13), and UDPD/creatinine (r = -0.15); P < 0.05 for all correlations. Multiple linear regression analysis showed that age, dietary vitamin D intake, multivitamin intake, and cooler season were independent positive predictors of serum 25OHD concentration (R2 = 0.18). The frequencies of VDR genotypes were 36% GG, 44.1% AG, and 19.9% AA. Allele frequencies were 58% for G allele and 42% for A allele and were in Hardy-Weinberg equilibrium (×2 = 1.44; P > 0.1). There was no statistically significant influence of VDR genotype on bone turnover or BMD. Conclusions: Vitamin D deficiency is highly prevalent in Emirati women and appears largely attributable to insufficient sunlight exposure. It is associated with increased bone turnover. VDR genotype does not appear to influence bone turnover markers or BMD in Emirati women.
KW - 25 hydroxyvitamin D
KW - Bone mineral density
KW - Bone turnover markers
KW - Emirati women
KW - Vitamin D receptor genotype
UR - http://www.scopus.com/inward/record.url?scp=33749531906&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33749531906&partnerID=8YFLogxK
U2 - 10.1016/j.bone.2006.05.010
DO - 10.1016/j.bone.2006.05.010
M3 - Article
C2 - 16814623
AN - SCOPUS:33749531906
SN - 8756-3282
VL - 39
SP - 1136
EP - 1143
JO - Bone
JF - Bone
IS - 5
ER -