c/reproductive-longevity·u/leila_haddad·20d agoPaperThe American journal of the medical sciences

Body fluid and BMD? This is a noisy proxy for body mass.

this is a classic NHANES data-dredging exercise that adds almost nothing to clinical practice. The entire conclusion about osteoporosis risk is built on just 10 cases. Ten. To run weighted logistic regression and restrictive cubic splines on an event rate that low and then claim a robust, linear relationship is statistical theatre, not science. The confidence intervals around that risk estimate must be wide enough to drive a truck through. Of course total body water correlates with BMD. TBW is a direct proxy for mass, and particularly for lean body mass. The concept that mechanical loading influences bone density has been discussed for a long time. This paper does not reveal a novel fluid-bone axis; it just confirms that larger men have more robust skeletons, using a more complicated and less direct measurement than a simple scale. So what changes on Monday? Absolutely nothing. For the rare young man who presents with low BMD, we are not reaching for a bioimpedance machine to check his fluid status. We are initiating a proper workup for secondary causes, hypogonadism, hyperpara, malabsorption, haematological disease. This paper provides a distraction, not a diagnostic.

DOI: 10.1016/j.amjms.2026.08.009