Low Comorbidity and Male Sex in Nonagenarian Community‐dwelling People Are Associated With Better Functional and Cognitive Abilities: The Nonasantfeliu Study

To the Editor: The nonagenarian population represents an unusual age group at the extreme limits of human life. Nonagenarians are predominantly female (and mostly widows), and an important proportion of them are functionally independent.1–4 Elderly women are more likely to be disabled than elderly men,3,4 and functional and cognitive status are worse in nonagenarians with higher comorbidity. The aim of this study was to evaluate the functional and cognitive capacity of a cohort of community-living nonagenarians and to assess the influence of sex and comorbidity on their incapacities. The NonaSantfeliu study is a population-based study of nonagenarian inhabitants in Sant Feliu de Llobregat (Barcelona, Spain). All 305 inhabitants aged 90 and older were contacted. Sixty-one percent replied (n=186). Participants did not differ significantly from nonparticipants according to age or sex. Institutionalization (n=49) was the only exclusion criterion. A geriatric assessment was conducted, and comorbidity (Charlson Comorbidity Index) and sociodemographic data were evaluated. The Barthel Index (BI) of basic activities of daily living (ADLs) and the Lawton and Brody scale for instrumental ADLs were measured. The Spanish version of the Mini-Mental State Examination (MEC),5 with a score up to 35 (≤23 indicates cognitive impairment), the short version of the Mini Nutritional Assessment questionnaire (short-MNA),6 and the Barber test (assesses social risk)7 were also used. Near visual acuity (Snellen chart) and hearing competence (Whisper test) were evaluated.8 Information on hypertension, diabetes mellitus, dyslipidemia, heart failure, stroke, ischemic cardiopathy, chronic obstructive pulmonary disease, and chronic drug prescription was collected. Nonincapacitated nonagenarians (successful aging) were considered to be those aged 90 and older scoring 91 or more on the BI and 24 or more on the MEC. They were compared with the rest. Normally distributed continuous variables are reported as means±standard deviations. Categorical variables are reported as proportions. The Student t test, the chi-square or Fisher exact, and multiple logistic regression analysis were performed. P<.05 indicated statistical significance The sample consisted of 99 women (72%) and 38 men; mean age was 93.1±0.7. There were 115 (84%) widowed, 15 (11%) married, and seven (5%) unmarried. Eighteen percent had dementia—25 of the 114 in the unsuccessful aging group. Fifty-six (41%) had a hearing impairment; 51 (37%) had a vision impairment, and 24 had (17.5%) combined sensorial impairment. The mean values of geriatric assessment were Lawton and Brody scale 2.5±2.3, BI 65.3±23.0, MEC 22±11, short-MNA 11.2±2.4, and Barber test 3.0±1.5. The mean Charlson Comorbidity Index was 1.43±1.7. Fifty-nine percent had hypertension, 14% diabetes mellitus, 17% dyslipidemia, 11% ischemic cardiopathy, 25% heart failure, and 15% chronic obstructive lung disease and 20% had suffered a stroke. Patients were taking an average of 4.1±2.4 drugs, and 76 patients (55%) took more than three drugs. The differences between the two groups are displayed in Table 1. Using multiple logistic regression analysis, successfully aging nonagenarians were significantly associated with male sex (odds ratio (OR)=4.23, 95% confidence interval (CI)=1.58–11.38; P=.004) and with lower comorbidity (OR=1.94; 95% CI=1.13–3.35; P=.01). Physical and cognitive dysfunction represent two of the most dreaded states in older people because they can lead to dependency and social isolation. In our study, in the more-successful aging group, a significant predominance of men was found. These results confirm previous data showing greater female incapacity within this age range.3,4 More than differences in incidence, the higher prevalence of disability in women may explain the greater survival rate of women with severe disability.3 Global comorbidity, evaluated using the Charlson Comorbidity Index, was higher in the group with worse functional and cognitive capacity. This unsuccessful aging group had a higher prevalence of patients who had previously had a stroke, but this did not attain significance in multivariate analyses. Loss of auditory acuity and sensory deprivation can affect some ADLs.9 The better-aging group had a lower percentage of visual and combined sensory deficits, not significant in the multivariate analysis. In the oldest old, several known predictors of mortality, such as sociodemographic factors, smoking, and obesity, have lost importance, but high disability level and poor physical and cognitive performance are useful for predicting mortality.10 This study has several limitations. We examined the association between current diseases and disability but did not evaluate previous disability. The small sample size, especially because of the few men included, may suggest some careful ratification to the sex differences found. In conclusion, male nonagenarians with low comorbidity probably undergo more successful aging than do women or those with high comorbidity. Financial Disclosure: Francesc Formiga, Assumpta Ferrer, Juan Manel Pérez-Castejon, Eduardo Henríquez, and Ramón Pujol all had no financial support, consultantships, speakers forum, or any company holdings or patents in relation to this article. Author Contributions: Francesc Formiga: study concept and design, drafting of the manuscript and study supervision. Assumpta Ferrer and Eduardo Henríquez: acquisition of data. Juan Manel Pérez-Castejon: study concept and design, and drafting of the manuscript. Ramón Pujol: critical revision of the manuscript for important intellectual content. Sponsor's Role: There were no sponsors for this article.