TY - JOUR
T1 - Calcium plus vitamin D supplementation and lung cancer incidence among postmenopausal women in the Women's Health Initiative
AU - Tao, Meng Hua
AU - Dai, Qi
AU - Chen, Shande
AU - Freudenheim, Jo L.
AU - Rohan, Thomas
AU - Wakelee, Heather
AU - Datta, Mridul
AU - Wactawski-Wende, Jean
N1 - Funding Information:
The WHI program is funded by the National Heart, Lung, and Blood Institute, National Institutes of Health, U.S. Department of Health and Human Services through contracts HHSN268201100046C, HHSN268201100001C, HHSN268201100002C, HHSN268201100003C, HHSN268201100004C, and HHSN271201100004C. This work was supported in part by the National Cancer Institute (R03CA184327). Dr. Qi Dai's effort was supported by R01 CA149633 and U01 CA182364.
Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2017/8
Y1 - 2017/8
N2 - Background Magnesium and calcium are antagonistic in many physiologic processes. However, few studies have investigated the associations of supplemental calcium with lung cancer risk taking this antagonism into account. We evaluated the effect of calcium and vitamin D supplementation on lung cancer incidence and explored whether the ratio of baseline calcium to magnesium (Ca:Mg) intake modifies the association in the Women's Health Initiative (WHI) calcium plus vitamin D supplementation (CaD) trial. Methods The intervention phase of the WHI CaD was a double-blinded, randomized, placebo-controlled trial in 36,382 postmenopausal women aged 50–79 years, recruited at 40 U.S. centers. Post-intervention follow-up continued among 29,862 (86%) of the surviving participants. Risk of lung cancer in association with CaD supplementation was evaluated using proportional hazard regression models. Results After 11 years’ cumulative follow-up, there were 207 lung cancers (incidence 0.11% per year) in the supplement arm and 241 (0.12%) in the placebo arm (hazard ratio (HR) for the intervention, 0.91; 95% confidence interval (CI), 0.71–1.17). Subgroup analyses suggested that the HR for lung cancer varied by baseline Ca:Mg intake ratio among women who were current smokers at enrollment (p = 0.04 for interaction). Conclusions Over the entire follow-up period, calcium and vitamin D supplementation did not reduce lung cancer incidence among postmenopausal women. In exploratory analyses, an interaction was found for the baseline Ca:Mg intake ratio on lung cancer among current smokers at the trial entry. This findings need to be further studied for the role of calcium with magnesium in lung carcinogenesis in current smokers.
AB - Background Magnesium and calcium are antagonistic in many physiologic processes. However, few studies have investigated the associations of supplemental calcium with lung cancer risk taking this antagonism into account. We evaluated the effect of calcium and vitamin D supplementation on lung cancer incidence and explored whether the ratio of baseline calcium to magnesium (Ca:Mg) intake modifies the association in the Women's Health Initiative (WHI) calcium plus vitamin D supplementation (CaD) trial. Methods The intervention phase of the WHI CaD was a double-blinded, randomized, placebo-controlled trial in 36,382 postmenopausal women aged 50–79 years, recruited at 40 U.S. centers. Post-intervention follow-up continued among 29,862 (86%) of the surviving participants. Risk of lung cancer in association with CaD supplementation was evaluated using proportional hazard regression models. Results After 11 years’ cumulative follow-up, there were 207 lung cancers (incidence 0.11% per year) in the supplement arm and 241 (0.12%) in the placebo arm (hazard ratio (HR) for the intervention, 0.91; 95% confidence interval (CI), 0.71–1.17). Subgroup analyses suggested that the HR for lung cancer varied by baseline Ca:Mg intake ratio among women who were current smokers at enrollment (p = 0.04 for interaction). Conclusions Over the entire follow-up period, calcium and vitamin D supplementation did not reduce lung cancer incidence among postmenopausal women. In exploratory analyses, an interaction was found for the baseline Ca:Mg intake ratio on lung cancer among current smokers at the trial entry. This findings need to be further studied for the role of calcium with magnesium in lung carcinogenesis in current smokers.
KW - Calcium
KW - Lung cancer
KW - Magnesium
KW - Randomized controlled trial
KW - Vitamin D
UR - http://www.scopus.com/inward/record.url?scp=85020248119&partnerID=8YFLogxK
U2 - 10.1016/j.lungcan.2017.06.002
DO - 10.1016/j.lungcan.2017.06.002
M3 - Article
C2 - 28676217
AN - SCOPUS:85020248119
SN - 0169-5002
VL - 110
SP - 42
EP - 47
JO - Lung Cancer
JF - Lung Cancer
ER -