Association between skin thickness and bone density in adult women.

Background: Osteoporosis mainly affects menopausal women and the elderly, predisposing these individuals to fractures that result in morbidity, mortality and costs to the healthcare system. Since dermal collagen reduces in parallel with a decrease in bone mass with aging, skin thickness may be indicative of a risk of osteoporosis.

Objectives: To evaluate the correlation between bone density and skin thickness on the backs of the hands of adult women.

Methods: A cross sectional study involving adult women attending a university hospital outpatient clinic who were interviewed individually and submitted to bone densitometry and measurement of skin thickness on the backs of their hands using skinfold calipers. Other risk factors for osteoporosis were also investigated.

Results: A total of 140 patients were evaluated. Mean age (± standard deviation) was 57 ± 11 years. Mean skin thickness on the backs of the hands was 1.4 ± 0.4 mm. There was a correlation between the right and left hands (R = 0.9; p<0.01). A direct correlation was found between skin thickness on the backs of the hands and bone density at the lumbar spine and femur (p<0.01). These results remained consistent even following adjustment for the covariables of age, skin phototype, body mass index, smoking, use of oral corticoids, anti-inflammatory use and time since menopause. Osteoporosis was inversely associated with the thickness of the skin on the back of the hands (odds ratio = 0.10; p<0.03)

Conclusion: An independent correlation was found between skin thickness and bone density, suggesting that these events occur simultaneously. Skin signs may represent a non-invasive method of stratifying risk in these patients, helping identify cases requiring early treatment.