Osteoporosis Linked to Increased Cataract Risk, Especially in Women

New research consistently demonstrates a significant association between osteoporosis and an increased risk of age-related cataracts, particularly among women. The findings, stemming from analyses of large-scale, ethnically diverse cohorts, highlight a potential bidirectional relationship between bone and eye health and offer new avenues for comprehensive health management in aging populations.

Study Details and Methodology

Researchers from the United Kingdom and Hong Kong conducted prospective cohort studies using data from the UK Biobank (UKB) and the Hong Kong Osteoporosis Study (HKOS). The UKB included 337,952 participants with a median follow-up of 13.5 years, while the HKOS involved 4,935 participants followed for a median of 18.5 years [1]. Bone mineral density (BMD) was assessed using dual-energy X-ray absorptiometry (DXA) in the HKOS and estimated bone mineral density (eBMD) derived from quantitative heel ultrasound in the UKB. Incident age-related cataracts were identified using International Classification of Diseases (ICD) codes.

Key Findings

Hong Kong Osteoporosis Study (HKOS) Results

Analysis of the HKOS cohort revealed that participants in the highest quartile of BMD T-scores had a significantly lower risk of cataracts compared to those in the lowest quartile. Individuals with osteopenia (T score between -2.5 and -1) and osteoporosis (T score ≤ -2.5) experienced a 24% and 34% increased risk of developing cataracts, respectively, compared to those with a BMD T score ≥ -1 [1]. This association was specifically observed in women.

UK Biobank (UKB) Results

In the UKB cohort, a diagnosis of osteoporosis was associated with a 16% increased risk of new cataracts. Subgroup analysis confirmed that this association was more pronounced in women [1].

Proteomic Mediation Analysis

To investigate the underlying biological mechanisms, researchers conducted proteomic mediation analysis within a subgroup of the UKB. Analysis of nearly 3,000 circulating proteins identified five potential mediators linking osteoporosis and cataracts: extracellular matrix phosphoglycoprotein (MEPE), growth differentiation factor 15 (GDF15), transmitcobalamin II (TCN2), CUB domain-containing protein 1 (CDCP1) and sialic acid-binding immunoglobulin-like lectin 1 (SIGLEC1) [1].

Implications and Future Research

This research supports the idea that osteoporosis and cataracts may be bidirectionally linked, rather than one simply causing the other. The identified mediator proteins offer new molecular insights into this association. Further research is needed to validate these findings in other cohorts and experimental studies.

The strong female-specific association may be related to declining estrogen levels, a major driver of osteoporosis in women, and its known association with cataract risk. But, the association remained significant even after adjusting for estradiol levels, suggesting other factors, such as sex-differential oxidative stress responses, may also play a role.

Clinical Significance

These findings emphasize the importance of comprehensive health management for older adults, particularly women. Increased ophthalmic surveillance, including screening for visual impairment and timely cataract intervention, may be beneficial for individuals with low BMD, alongside optimized fracture prevention measures. This integrated approach could synergistically reduce the risk of falls and fractures in older adults.