Clinical Epidemiology (Jul 2018)
Association of obesity, diabetes and hypertension with cognitive impairment in older age
Abstract
Insa Feinkohl,1,* Gunnar Lachmann,2,* Wolf-Rüdiger Brockhaus,2 Friedrich Borchers,2 Sophie K Piper,3 Thomas H Ottens,4 Hendrik M Nathoe,5 Anne-Mette Sauer,4 Jan M Dieleman,4 Finn M Radtke,6 Diederik van Dijk,7 Tobias Pischon,1,8,9,* Claudia Spies2,* 1Molecular Epidemiology Research Group, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin-Buch, Germany; 2Department of Anesthesiology and Operative Intensive Care Medicine (CCM, CVK), Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; 3Institute of Biometry and Clinical Epidemiology, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; 4Department of Anesthesiology, University Medical Center Utrecht, Utrecht, the Netherlands; 5Department of Cardiology, University Medical Center Utrecht, Utrecht, the Netherlands; 6Department of Anesthesiology, Naestved Hospital, Naestved, Denmark; 7Department of Intensive Care Medicine, University Medical Center Utrecht, Utrecht, the Netherlands; 8Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; 9MDC/BIH Biobank, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), and Berlin Institute of Health (BIH), Berlin, Germany *These authors contributed equally to this work Background: Age-related cognitive impairment is rising in prevalence but is not yet fully characterized in terms of its epidemiology. Here, we aimed to elucidate the role of obesity, diabetes and hypertension as candidate risk factors. Methods: Original baseline data from 3 studies (OCTOPUS, DECS, SuDoCo) were obtained for secondary analysis of cross-sectional associations of diabetes, hypertension, blood pressure, obesity (body mass index [BMI] ≥30 kg/m²) and BMI with presence of cognitive impairment in log-binomial regression analyses. Cognitive impairment was defined as scoring more than 2 standard deviations below controls on at least one of 5–11 cognitive tests. Underweight participants (BMI<18.5 kg/m2) were excluded. Results were pooled across studies in fixed-effects inverse variance models. Results: Analyses totaled 1545 participants with a mean age of 61 years (OCTOPUS) to 70 years (SuDoCo). Cognitive impairment was found in 29.0% of participants in DECS, 8.2% in SuDoCo and 45.6% in OCTOPUS. In pooled analyses, after adjustment for age, sex, diabetes and hypertension, obesity was associated with a 1.29-fold increased prevalence of cognitive impairment (risk ratio [RR] 1.29; 95% CI 0.98, 1.72). Each 1 kg/m² increment in BMI was associated with 3% increased prevalence (RR 1.03; 95% CI 1.00, 1.06). None of the remaining risk factors were associated with impairment. Conclusion: Our results show that older people who are obese have higher prevalence of cognitive impairment compared with normal weight and overweight individuals, and independently of co-morbid hypertension or diabetes. Prospective studies are needed to investigate the temporal relationship of the association. Keywords: obesity, body mass index, diabetes, hypertension, cognitive impairment, aging, cognitive epidemiology