Diabetes and the risk of multi-system aging phenotypes: a systematic review and meta-analysis.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of prospective cohort studies
PubMed 19127292 · doi:10.1371/journal.pone.0004144
What was done
MEDLINE and PsycINFO databases were searched through November 2007 along with bibliography checks for population-based, prospective cohort studies examining baseline diabetes mellitus (DM) in relation to geriatric outcomes. Two reviewers independently extracted study population, follow-up length, DM ascertainment, outcome measures, and adjusted covariates.
What was found
Fifteen studies evaluated cognitive dysfunction: DM was associated with faster cognitive decline, with pooled adjusted risk ratios (RRs) of 1.47 (95% CI, 1.25 to 1.73) for all-cause dementia, 1.39 (95% CI, 1.16 to 1.66) for Alzheimer's disease, and 2.38 (95% CI, 1.79 to 3.18) for vascular dementia. Four of 5 studies found a significant association between DM and faster mobility decline and incident disability. Two studies in older women linked DM to falls (with higher recurrent fall risk in insulin users), and 1 study linked DM to urinary incontinence. Two studies did not find DM to be an independent predictor of incident depression.
Why it matters
This review aggregates prospective evidence showing that diabetes substantially increases the risk of multiple geriatric conditions, particularly vascular and non-vascular dementia, highlighting the multisystem impact of diabetes on aging.
Limits
The underlying evidence consists entirely of observational cohort studies, precluding causal conclusions. Non-cognitive geriatric outcomes (falls, incontinence, depression) relied on very small numbers of studies (1–2 each). The abstract does not report the total participant sample size, heterogeneity metrics, or numerical risk estimates for non-cognitive endpoints.
Cited by
- contradicts Having type 2 diabetes makes a person's risk of developing dementia four times higher.