Biological determinants of postural disorders in elderly women.

Postural control impairments and dizziness, which are major health problems with high secondary morbidity and mortality, increase with aging. Elevated homocysteine (Hcy) level is an age-related metabolic disorder, known to be involved in cardiovascular, neurological, and multisensory dysfunctions. Elevated Hcy level might be involved in sensory balance control systems impairment and dizziness occurrence. Dizziness, fitness Instrumental Activity of Daily Living scale (fitness IADL), systolic arterial pressure with ankle-brachial blood pressure index and homocysteinemia were studied in 61 noninstitutionized elderly women. Clinical balance tests (timed "Up and Go", 10-m walking and one-leg balance) and posturography (including sensory conflicting situations [SCS] and cognitive conflicting situations [CCS]) were performed. Clinical balance control was lower in dizzy women who presented particularly poor stability in SCS. Dizziness was related to low fitness IADL scores (odds ratio [OR] 0.452, 95% CI 0.216-0.946) and to elevated Hcy (OR 8.084, 95% CI 1.992-32.810). Elevated Hcy was correlated with balance disorders both in SCS and CCS. Dizziness is associated with a reduced ability in balance control management. Hcy is related both to dizziness and low postural performance. This relation between elevated Hcy levels and balance impairments, resulting in dizziness, may be explained by its angiotoxicity and neurotoxicity.