# 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.

## Key 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.