Elderly patients with diabetes at high risk of falls
A study, in Diabetes Care, has shown that low HbA1c in older patients using insulin increases the risk of falls.
The multicentre study from the US used patients with diabetes from the Health, Aging, and Body Composition (Health ABC) Study as a cohort for a prospective longitudinal study. The study included 446 patients, of whom 55% were men and 53% were white. All the participants were independent in activities of daily living and could walk up 10 steps and a quarter of a mile.
Baseline examinations were performed in 1997-98. The average age at baseline was 73.6, and the average duration of diabetes 12.8 years. Patients were assessed annually and average follow-up was for 4.9 years.
At each visit, participants were assessed and asked, ‘In the past 12 months have you fallen and landed on the floor or ground?' Assessments included physical performance, assessing balance, grip strength and stamina; visual contrast sensitivity, a marker of retinopathy and visual loss; peroneal nerve response amplitude, a marker of neuropathy; and cystatin-C, a marker of poor renal function and nephropathy. HbA1c was also measured.
In the first year, 23% of the patients reported falling, a figure that rose to 31% in year five. Reduced peroneal nerve response amplitude, higher cystatin-C and poorer contrast sensitivity were all associated with an increase in falls. Low HbA1c (? 6.0%) in patients using insulin, but not those using tablets, was associated with an increased risk of falls.
Falls in older people are a sensitive marker of impending deterioration in health, increasing the risk of loss of independence, hospitalisation and even death. Initiatives to prevent hospital admissions by supporting vulnerable patients use a recent fall as one of their criteria. Several studies have shown that older adults with type 2 diabetes have an increased risk of falls.1,2
It seems reasonable to expect that poor vision and reduced sensation in the extremities might predispose patients to falls. Low HbA1c, with the increased risk of hypoglycaemia, also seems a logical finding. It is interesting to note that poor renal function is also a risk factor, and that tight control achieved with oral hypoglycaemics carries less risk of a fall than using insulin.
These findings may help those in primary care to refine models of elderly patients at risk. They also suggest that efforts to prevent microvascular complications from developing or proceeding may be an excellent long-term investment for the health of an ageing population.
Schwartz AV, Vitinghoff E, Sellmeyer D et al. Diabetes-related Complications, Glycaemic Control, and Falls in Older Adults. Diabetes Care 2008:31,391-6Reviewer
Dr Matthew Lockyer
GP, Suffolk and hospital practitioner in diabetic medicine