TY - JOUR
T1 - The association between circulating IGF1, IGFBP3, and calcium
T2 - Results from NHANES III
AU - Van Hemelrijck, Mieke
AU - Shanmugalingam, Thurkaa
AU - Bosco, Cecilia
AU - Wulaningsih, Wahyu
AU - Rohrmann, Sabine
PY - 2015/9
Y1 - 2015/9
N2 - Background: Despite mounting evidence linking both calcium and IGF1, there is a lack of studies investigating any association between circulating levels of IGF1 and serum calcium. Methods: Serum calcium, IGF1, and IGF-binding protein 3 (IGFBP3) were measured for 5368 participants in NHANES III. We calculated multivariable-adjusted geometric means of serum concentrations of IGF1, IGFBP3, and IGF1/IGFBP3 by categories of calcium (lowest 5% (<1.16 mmol/l), mid 90%, and top 5% (≥1.31 mmol/l)). We also performed stratified analyses by sex, age, ethnicity, BMI, serum levels of vitamin D, and bone mineral density (BMD). Results: Overall, we found that circulating calcium was positively associated with circulating levels of IGF1 and IGFBP3, but not their molar ratio (i.e., geometric mean of IGF1 by increasing calcium categories: 237.63, 246.51, and 264.22 ng/nl; Ptrend: 0.43; Pfirst vs third category: 0.01). In particular, these associations were observed in women, people aged<60, non-Hispanic whites, those with vitamin D levels above the mean, and those with low BMD. In contrast, there was an inverse association with the molar ratio for those with BMI ≥30 kg/m2. Conclusion: We found an overall positive association between circulating levels of IGF1 and IGFBP3 and serum calcium. However, stratification by potential effect-modifiers did not support all suggested hypotheses. Our findings provide more insight into the interplay between calcium and IGF1, which in the future can be investigated in larger observational studies allowing for additional stratifications based on a combination of the different effect-modifiers investigated here.
AB - Background: Despite mounting evidence linking both calcium and IGF1, there is a lack of studies investigating any association between circulating levels of IGF1 and serum calcium. Methods: Serum calcium, IGF1, and IGF-binding protein 3 (IGFBP3) were measured for 5368 participants in NHANES III. We calculated multivariable-adjusted geometric means of serum concentrations of IGF1, IGFBP3, and IGF1/IGFBP3 by categories of calcium (lowest 5% (<1.16 mmol/l), mid 90%, and top 5% (≥1.31 mmol/l)). We also performed stratified analyses by sex, age, ethnicity, BMI, serum levels of vitamin D, and bone mineral density (BMD). Results: Overall, we found that circulating calcium was positively associated with circulating levels of IGF1 and IGFBP3, but not their molar ratio (i.e., geometric mean of IGF1 by increasing calcium categories: 237.63, 246.51, and 264.22 ng/nl; Ptrend: 0.43; Pfirst vs third category: 0.01). In particular, these associations were observed in women, people aged<60, non-Hispanic whites, those with vitamin D levels above the mean, and those with low BMD. In contrast, there was an inverse association with the molar ratio for those with BMI ≥30 kg/m2. Conclusion: We found an overall positive association between circulating levels of IGF1 and IGFBP3 and serum calcium. However, stratification by potential effect-modifiers did not support all suggested hypotheses. Our findings provide more insight into the interplay between calcium and IGF1, which in the future can be investigated in larger observational studies allowing for additional stratifications based on a combination of the different effect-modifiers investigated here.
KW - Calcium
KW - Cross-sectional
KW - IGF-1
KW - IGFBP3
UR - http://www.scopus.com/inward/record.url?scp=85026816866&partnerID=8YFLogxK
U2 - 10.1530/EC-15-0039
DO - 10.1530/EC-15-0039
M3 - Article
AN - SCOPUS:85026816866
SN - 2049-3614
VL - 4
SP - 187
EP - 195
JO - Endocrine Connections
JF - Endocrine Connections
IS - 3
ER -