Threshold Effects of Body Mass Index on the Bone Mineral Density of Chinese Rural Women in Fluorosis Area

To explore the threshold effect of body mass index (BMI) on bone mineral density (BMD) in Chinese women living in the fluorosis area, we conducted a cross-sectional study and recruited 722 women in rural areas in Henan Province, China. After detection and analyses, we found that compared with the normal BMI group, the risk of osteoporosis in the overweight and obese groups were reduced by 32% and 69%, respectively. Threshold effect analysis showed that BMD was positively correlated with BMI when BMI was 16.8-31.2 kg/m 2; while when BMI was greater than 31.2 kg/m 2, the correlation reached saturation. The correlation observed between low-to-moderate fluoride exposure and BMD in rural women was not significant.