Vitamin D status and functional performance in peripheral artery disease
Vascular Medicine, 07/24/2012
McDermott MM et al. – Vitamin D deficiency is common among people with peripheral artery disease (PAD) encountered in clinical settings. After adjusting for body mass index (BMI) and diabetes mellitus, authors found no significant associations of lower levels of 25–hydroxyvitamin D with poorer functional performance or calf muscle characteristics. Associations of low vitamin D levels with poorer peripheral nerve function require further study.Methods
- The clinical implications of low vitamin D in peripheral artery disease (PAD) are unknown.
- Authors hypothesized that among individuals with PAD, lower levels of 25–hydroxyvitamin D would be associated with poorer functional performance, more adverse calf muscle characteristics, and poorer peripheral nerve function.
- Participants were 402 men and women with PAD who underwent measurement of 25–hydroxyvitamin D (DiaSorin radioimmunoassay) along with 6–minute walk testing, measurement of walking velocity at usual and fastest pace, computed tomography–measured calf muscle density, and peripheral nerve conduction velocity (NCV).
- Among PAD participants, 20.4% had 25–hydroxyvitamin D levels < 30 nmol/L, consistent with deficient vitamin D status.
- Adjusting for age, sex, and race, lower 25–hydroxyvitamin D levels were associated with poorer 6–minute walk performance (p trend = 0.002), slower usual–paced 4–meter walking velocity (p trend = 0.031), slower fast–paced 4–meter walking velocity (p trend = 0.043), and lower calf muscle density (p trend = 0.031).
- After additional adjustment for body mass index (BMI) and diabetes, none of these associations remained statistically significant.
- However, lower levels of 25–hydroxyvitamin D were associated with poorer peroneal NCV (p trend = 0.013) and poorer sural NCV (p trend = 0.039), even after adjusting for age, sex, race, BMI, comorbidities, smoking, physical activity, and other confounders.