High Levels of Serum Phosphorus Are Associated with Reduced Percentages of Body Fat: A Cross-sectional Study

An excessively high percentage of body fat can increase the risk of developing heart disease, diabetes, and other chronic diseases. This study examined two research questions: (1) What is the effect of serum phosphorus on the percentage of body fat? and (2) Does serum phosphorus have a different effect on the percentage of body fat in different parts of the body? This study investigated these questions using data from the National Health and Nutrition Examination Survey (NHANES). Nutritional and biochemical data were collected from the NHANES database from 2011 to 2018 on 15,653 participants, including 8,014 men and 7,639 women. Dual-energy X-ray absorptiometry (DXA) was used to assess the percentage of body fat of the study participants at the following body sites: the head, left arm, right arm, left leg, right leg, and trunk. Multivariate logistic regression was used to assess the odds ratios for excess fat percentages at several body sites in relation to serum phosphorus levels. The analyses found that high levels of serum phosphorus were associated with a smaller percentage of excess body fat in some areas of the body. Specifically, serum phosphorus levels exhibited a curvilinear association with increased body fat in the trunk, left arm, and right arm of females. As serum phosphorus levels increased in males, their percentage of body fat decreased in the trunk, left leg, right arm, and right leg.