Background: Frailty is an age-related syndrome characterized by reductions in strength, endurance, and physiologic function that increase an individual’s vulnerability for developing dependence or death.
Extensive research is being conducted to determine preventable risk factors and mechanistic pathways of this syndrome, whose prevalence in Europe and the US is around 10-15% of the community-dwelling elderly.
Methods: Four studies were conducted. The first was a review of the scientific literature on the association between environmental pollutants, limitations in physical functioning, and frailty among older adults. The other 3 were observational studies aimed to evaluate: 1) the association between secondhand tobacco smoke and the frailty syndrome in the nonsmoking community-dwelling US elderly population (n=2509); 2) the association between biomarkers of lead and cadmium exposure and the frailty syndrome among US adults aged ≥60years (n=5272); and 3) the association between biomarkers of cadmium exposure and walking speed among US adults aged ≥50 years (n=3226).
Results: Very few studies have previously evaluated the association between environmental pollutants and frailty or its components. Lead, cadmium and secondhand smoke, are among the pollutants for which we have found evidence that they may be associated with the frailty syndrome. In our studies, the adjusted odds ratios (95 %CI) of frailty comparing the second, third, and fourth quartiles of serum cotinine to the lowest were, respectively, 1.44 (0.67–3.06), 1.46 (0.75–2.85), and 2.51 (1.06–5.95), p value for trend 0.04. The corresponding OR for lead tertiles were, respectively, 1.40 (0.96-2.04) and 1.75 (1.33-2.31), p value for trend <0.01. Finally, the highest (vs. lowest) quintile of blood cadmium was associated with a 0.18 (95% CI: 0.10, 0.25) ft/sec reduction in walking speed (p-Trend <0.001).
Conclusion: There is a need for more studies to assess the effects of environmental pollution on frailty. Environmental and geriatric epidemiologists should work together to address important research challenges.