Association of Serum Estradiol and Testosterone With Hip Fractures in Elderly Men

TL;DR

Lower levels of testosterone and estradiol in elderly men are linked to a higher risk of hip fractures, suggesting a role for sex hormones in male bone health.

Contribution

This study is among the first to investigate the association between serum estradiol and testosterone levels with hip fractures in elderly South Indian men.

Findings

Elderly men with hip fractures had significantly lower testosterone and estradiol levels compared to healthy controls.

A high prevalence of androgen deficiency was observed in men with hip fractures.

Low estradiol levels were more common in fracture cases than in controls.

Abstract

Introduction: Hip fractures in the elderly are a major public health concern due to high morbidity, mortality, and long-term disability. While men have a lower incidence of hip fractures than women, the risk rises sharply with age, and outcomes in men are often worse. Sex steroids (especially estrogen and testosterone) play a crucial role in bone metabolism, but their contribution to osteoporosis and fracture risk in elderly men remains under-investigated, particularly in diverse populations. This prospective case-control study aimed to determine whether serum estradiol and testosterone levels differ significantly between elderly South Indian men with osteoporotic hip fractures and age-matched healthy controls.

Methods: A prospective case-control study was conducted on men over 55 years of age at a South Indian tertiary hospital (March-May 2022). Fifty men with osteoporotic hip fractures (cases) and 50 age-matched healthy male controls were recruited. Clinical data (age, body mass index, smoking status) were collected, and serum total estradiol and testosterone levels were measured using enzyme-linked fluorescent immunoassay. Overt androgen deficiency was defined as total testosterone <2 ng/mL, and possible deficiency as 2-4 ng/mL. Group comparisons were performed using independent t-tests or Mann-Whitney tests for continuous variables and Fisher’s exact test for categorical variables, with significance set at p<0.05.

Results: The majority of hip fracture cases were in the 65-75 years age group (25, 50%). Cases had a high prevalence of low sex hormones: 22 (44%) had overt androgen deficiency and 26 (52%) had possible androgen deficiency, compared to only two (4%) of controls with testosterone <2 ng/mL. Mean serum testosterone in cases was significantly lower than in controls (2.40±1.12 vs. 4.22±1.62 ng/mL, p<0.001), and mean estradiol was also lower in cases (32.07±10.08 vs 41.88±17.99 pg/mL, p=0.008). Low estradiol levels were more frequent in cases: only 21 (42%) of cases had high-normal estradiol (≥34.3 pg/mL) vs. 30 (60%) of controls. There were no significant differences in body mass index or smoking status between cases and controls (p>0.05).

Conclusion: Elderly men with hip fractures had significantly lower serum testosterone and estradiol levels than age-matched controls, demonstrating an association between reduced sex hormone levels and hip fracture status. These findings support a possible role of sex hormones in male skeletal health, but causal relationships and therapeutic implications cannot be inferred from this study and require confirmation in larger prospective investigations.