Does the metabolic syndrome predict mobility impairment in the elderly?

The predictive importance of the metabolic syndrome and its components for declining mobility were tested in a 5-year follow-up study of four elderly birth cohorts (65, 75, 80 and 85 years of age; n=946). In the age group of 65 years, the subjects with mobility decline were more often diabetics (24.6 vs. 15.5%, P=0.060), had higher blood glucose (6.2 vs. 5.8 mmol/l, P<0.05), higher fasting plasma insulin (13.2 vs. 11.4 IU/l, P<0.01), and higher body mass index (28.4 vs. 27.2 kg/m(2), P<0.05) than the others. In the 75 year-old group, the mobility decline was associated with lower HDL-cholesterol (1.4 vs. 1.6 mmol/l, P<0.05) and higher insulin (15.9 vs. 12.8 IU/l, P<0.10). In the 80 year-old group, insulin was higher in subjects whose mobility declined (11.3 vs. 17.9 IU/l, P<0.05) but in the oldest group insulin tended to be lower in the subjects with declining mobility. In non-diabetic subjects, blood glucose and plasma insulin were associated with declining mobility in the 65 year-old cohort, only. After controlling for gender and baseline mobility, one quartile of both insulin and BMI increased the probability of mobility decline by 35%, mainly of difficulties in walking up stairs. Of the components of metabolic syndrome, obesity and hyperinsulinemia as its consequence appear causal of declining mobility.