Dietary Supplement Use in Older People Attending Memory Clinics in Australia.

BACKGROUND

Dietary supplement use is common in older adults. There has been limited research in people attending memory clinics.

OBJECTIVES

To explore the use of dietary supplements in older people attending Australian memory clinics.

DESIGN

Cross-sectional analysis of baseline data from the Prospective Research In MEmory clinics (PRIME) study.

PARTICIPANTS

Community-dwelling older people who attended nine memory clinics and had a diagnosis of mild cognitive impairment (MCI) or dementia.

MEASUREMENTS

Dietary supplement was defined as a product that contains one or more: vitamin, mineral, herb or other botanical, amino acid or other dietary substance. Non-prescribed supplement was defined as a supplement that is not usually prescribed by a medical practitioner. Polypharmacy was defined as use of five or more medications.

RESULTS

964 patients, mean age 77.6 years, were included. Dietary supplements were used by 550 (57.1%) patients; 353 (36.6%) used two or more. Non-prescribed supplements were used by 364 (36.8%) patients. Supplement use was associated with older age (OR: 1.12, 95% CI: 1.03-1.21), lower education level (OR: 1.53, 95% CI: 1.01-2.32) and a diagnosis of MCI rather than dementia (OR: 1.52, 95% CI: 1.05-2.21). Potential drug-supplement interactions were identified in 107 (11.1%) patients. Supplement users had increased prevalence of polypharmacy compared to non-users (80.5% vs. 48.1%, p<0.001).

CONCLUSIONS

Dietary supplements, including non-prescribed supplements, were commonly used by people attending memory clinics. Supplement use increased the prevalence of polypharmacy and resulted in potential supplement-drug interactions. Further research is required to assess the clinical outcomes of supplement use.