TY - JOUR
T1 - Effect of Vitamin D replacement on indexes of insulin resistance in overweight elderly individuals
T2 - A randomized controlled trial
AU - Fuleihan, Ghada El Hajj
AU - Baddoura, Rafic
AU - Habib, Robert H.
AU - Halaby, Georges
AU - Arabi, Asma
AU - Rahme, Maya
AU - Singh, Ravinder J.
AU - Kassem, Moustapha
AU - Mahfoud, Ziyad
AU - Hoteit, Maha
AU - Daher, Rose T.
AU - Kassir, Mohamed Faisal
N1 - Funding Information:
Supported by governmental and institutional funds from the American University of Beirut, St. Joseph University, the Lebanese Council for National Scientific Research, and in part by NIH Fogary International Center and Office of Dietary Supplements grant 3D43TW009-118-03W1. Assays performed outside the American University of Beirut were supported in part by institutional grants from the Mayo Clinic and Odense University.
Publisher Copyright:
© 2016 American Society for Nutrition.
PY - 2016/8/1
Y1 - 2016/8/1
N2 - It is unclear whether and at what dose vitamin D supplementation affects insulin resistance (IR). Objective: We sought to investigate whether vitamin D at doses higher than currently recommended decreases indexes of IR in an ambulatory population of overweight elderly subjects. Design: This double-blind, randomized, controlled multicenter trial enrolled 257 elderly overweight individuals aged ≥ 65 y with baseline 25-hydroxyvitamin D [25(OH)D] concentrations between 10 and 30 ng/mL. All subjects received 1000 mg calcium citrate/d, with vitamin D administered weekly at an equivalent dose of 600 or 3750 IU/d. The homeostasis model assessment (HOMA) of IR index at 1 y was the primary outcome.We also assessed the McAuley index. Results: In total, 222 subjects (55% women) with a mean ± SD age and body mass index (BMI; in kg/m2) of 71 ± 4 y and 30 ± 4, respectively, completed the study. Subjects' baseline characteristics, including IR indexes, were similar across groups: 69% had prediabetes, 54% had hypertension (47% were taking antihypertensive medications), and 60% had hyperlipidemia, nearly half of whom were receiving lipidlowering drugs. At 1 y, mean ± SD serum 25(OH)D increased from 20 ± 7 to 26 ± 7 ng/mL in the low-dose arm (P <0.0001) and from 21 ± 8 to 36 ± 10 ng/mL in the high-dose arm (P > 0.001). Median HOMA-IR indexes did not change compared with baseline concentrations and were similar in the high-[2.2 (IQR: 1.5, 2.9)] and low-dose [2.3 (IQR: 1.6, 3.3] treatment groups. Adjusted analyses showed that HOMA-IR was predicted by the baseline HOMA index and BMI but not by vitamin D dose, baseline serum 25(OH)D, or change in 25(OH)D. Conclusion: Vitamin D3 at 3750 IU/d did not improve HOMA-IR compared with the Institute of Medicine Recommended Dietary Allowance of 600 IU/d in elderly overweight individuals.
AB - It is unclear whether and at what dose vitamin D supplementation affects insulin resistance (IR). Objective: We sought to investigate whether vitamin D at doses higher than currently recommended decreases indexes of IR in an ambulatory population of overweight elderly subjects. Design: This double-blind, randomized, controlled multicenter trial enrolled 257 elderly overweight individuals aged ≥ 65 y with baseline 25-hydroxyvitamin D [25(OH)D] concentrations between 10 and 30 ng/mL. All subjects received 1000 mg calcium citrate/d, with vitamin D administered weekly at an equivalent dose of 600 or 3750 IU/d. The homeostasis model assessment (HOMA) of IR index at 1 y was the primary outcome.We also assessed the McAuley index. Results: In total, 222 subjects (55% women) with a mean ± SD age and body mass index (BMI; in kg/m2) of 71 ± 4 y and 30 ± 4, respectively, completed the study. Subjects' baseline characteristics, including IR indexes, were similar across groups: 69% had prediabetes, 54% had hypertension (47% were taking antihypertensive medications), and 60% had hyperlipidemia, nearly half of whom were receiving lipidlowering drugs. At 1 y, mean ± SD serum 25(OH)D increased from 20 ± 7 to 26 ± 7 ng/mL in the low-dose arm (P <0.0001) and from 21 ± 8 to 36 ± 10 ng/mL in the high-dose arm (P > 0.001). Median HOMA-IR indexes did not change compared with baseline concentrations and were similar in the high-[2.2 (IQR: 1.5, 2.9)] and low-dose [2.3 (IQR: 1.6, 3.3] treatment groups. Adjusted analyses showed that HOMA-IR was predicted by the baseline HOMA index and BMI but not by vitamin D dose, baseline serum 25(OH)D, or change in 25(OH)D. Conclusion: Vitamin D3 at 3750 IU/d did not improve HOMA-IR compared with the Institute of Medicine Recommended Dietary Allowance of 600 IU/d in elderly overweight individuals.
KW - HOMA
KW - High-dose Vitamin D
KW - IOM RDA
KW - Insulin resistance
KW - Prediabetes
UR - http://www.scopus.com/inward/record.url?scp=84980373313&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84980373313&partnerID=8YFLogxK
U2 - 10.3945/ajcn.116.132589
DO - 10.3945/ajcn.116.132589
M3 - Article
C2 - 27413130
AN - SCOPUS:84980373313
SN - 0002-9165
VL - 104
SP - 315
EP - 323
JO - American Journal of Clinical Nutrition
JF - American Journal of Clinical Nutrition
IS - 2
ER -