Associations of body habitus and its changes with incident dementia in older adults.

BACKGROUND: This study examined the associations of body mass index (BMI) and waist circumference (WC), as well as their short- and long-term changes over time, with incident dementia in older individuals. METHODS: Data came from 18,837 community-dwelling individuals aged 65+ years from Australia and the United States, who were relatively healthy without major cognitive impairment at enrolment. Anthropometric measures were prospectively assessed at baseline, as well as change and variability from baseline to year two (three time-points). In a subgroup (n = 11,176), self-reported weight at age 18 and 70+ years was investigated. Dementia cases satisfied DSM-IV criteria. Cox regression was used to examine the associations between anthropometric measures and incident risk of dementia. RESULTS: Compared to normal weight, an overweight (HR: 0.67, 95%CI: 0.57-0.79, p < 0.001) or obese BMI (HR: 0.73, 95%CI: 0.60-0.89, p = 0.002), or a larger WC (elevated, HR: 0.71, 95%CI: 0.58-0.86, p < 0.001; highly elevated, HR: 0.65, 95%CI: 0.55-0.78, p < 0.001; relative to low) at baseline was associated with lower dementia risk. In contrast, substantial increases in BMI (>5%) over 2 years after baseline were associated with higher dementia risk (HR: 1.49, 95% CI: 1.17-1.91, p = 0.001). Increased dementia risk was also seen with an underweight BMI at baseline and a 2-year BMI decrease (>5%), but these associations appeared only in the first 4 years of follow-up. Compared to normal weight at both age 18 and 70+ years, being obese at both times was associated with increased dementia risk (HR: 2.27, 95%CI: 1.22-4.24, p = 0.01), while obesity only at age 70+ years was associated with decreased risk (HR: 0.70, 95%CI: 0.51-0.95, p = 0.02). CONCLUSIONS: Our findings suggest that long-term obesity and weight gain in later life may be risk factors for dementia. Being underweight or having substantial weight loss in old age may be early markers of pre-clinical dementia.

Socio-Demographic, Lifestyle, and Clinical Characteristics of Early and Later Weight Status in Older Adults: Secondary Analysis of the ASPREE Trial and ALSOP Sub-Study.

OBJECTIVE: To identify the socio-demographic, lifestyle, and clinical characteristics associated with self-reported weight status in early (age 18 years) and late (age ≥ 70 years) adulthood. METHODS: The number of participants was 11,288, who were relatively healthy community-dwelling Australian adults aged ≥70 years (mean age 75.1 ± 4.2 years) in the Aspirin in Reducing Events in the Elderly (ASPREE) Longitudinal Study of Older Persons (ALSOP) sub-study. Self-reported weight at the study baseline (age ≥ 70 years) and recalled weight at age 18 years were collected. Height measured at baseline was used to calculate the BMI at both time points. Individuals were categorised into one of five 'lifetime' weight status groups: healthy weight (at both age 18 year and ≥70 years), overweight (at either or both times), non-obese (age 18 year) to obesity (age ≥70 years), obesity (age 18 years) to non-obese (age ≥ 70 years), and early and later life obesity (at age 18 years and ≥70 years). RESULTS: Participants who experienced obesity in early and/or late adulthood were at a higher risk of adverse clinical characteristics. Obesity in late adulthood (regardless of early adulthood weight status) was associated with high proportions of hypertension, diabetes, and dyslipidaemia, whereas obesity in early adulthood (regardless of late adulthood weight status) was associated with lower cognitive scores (on all four measures). DISCUSSION/CONCLUSION: Healthy or overweight weight status in early and later adulthood was associated with more favourable socioeconomic, lifestyle, and clinical measures. Obesity in early adulthood was associated with lower cognitive function in later adulthood, whereas obesity in later adulthood was associated with hypertension, diabetes, and dyslipidaemia.

Objectively Assessed Weight Change and All-Cause Mortality among Community-Dwelling Older People.

Later life changes in body weight may be associated with an increased risk of mortality in older adults. The objective of this study was to examine whether weight change over four years was associated with a 17-year mortality risk in older adults. Participants were 1664 community-dwelling adults aged ≥65 years in the longitudinal Enquete de Sante' Psychologique-Risques, Incidence et Traitement (ESPRIT) study. Outcomes were all-cause mortality, cardiovascular disease (CVD) and cancer mortality. Weight change was defined as difference between weight at baseline and 4 years, categorised into: weight stable (±<5% weight change), weight loss (≥5%) and weight gain (≥5%). Association between weight change and mortality risk was evaluated using Cox proportional hazards models. Over 17 years of follow-up (median 15 years), 565 participants died. Compared to stable weight participants, those with ≥ 5% weight loss had an increased risk of all-cause mortality (HR: 1.24, 95% CI: 1.00−1.56, p = 0.05) and CVD mortality (HR: 1.53, 95% CI: 1.10−2.14, p = 0.01), but not cancer mortality (HR: 0.83, 95% CI: 0.50−1.39, p = 0.49). Weight gain of ≥5% was not associated with increased mortality (HR: 1.05, 95% CI: 0.76−1.45, p = 0.74). Weight monitoring in older adults could help identify weight loss at its early stages to better target interventions to maintain nutritional reserve and prevent premature mortality.

The Association of Weight Loss, Weight Status, and Abdominal Obesity with All-Cause Mortality in Older Adults.

OBJECTIVES: The objectives of this study were to examine whether weight loss, weight status (based on body mass index [BMI] categories), and abdominal obesity (based on waist circumference [WC]) were associated with a 17-year mortality risk in community-dwelling older adults. METHODS: Participants were 2,017 community-dwelling adults aged 65 years or above in the longitudinal Enquête de Santé Psychologique-Risques, Incidence et Traitement study. Self-reported weight loss was collected at baseline during face-to-face interviews. Bodyweight (kg), height (m), and WC (cm) were independently measured at the baseline. BMI was categorized as follows: underweight (BMI <18.5 kg/m2), normal weight (18.5-24.9 kg/m2), overweight (25-29.9 kg/m2), and obese (≥30 kg/m2). Abdominal obesity was defined by a WC of ≥102 cm in men and ≥88 cm in women. Adjusted Cox proportional hazards models were used to examine associations of weight loss, weight status, and abdominal obesity with all-cause mortality. RESULTS: Over 17 years of follow-up (median 15.5 years), 812 participants died. Abdominal obesity compared to nonabdominal obesity was associated with a 49% increased mortality risk (95% confidence interval (CI): 1.22-1.83). However, being overweight (but not obese) was associated with a 20% decreased risk (95% CI: 0.66-0.97) compared to a normal BMI. Gender did not affect these associations. In the whole cohort, self-reported weight loss at baseline was not associated with an increased mortality risk after adjusting for health and lifestyle factors. However, in men, a baseline self-reported recent weight loss of >3 kg was associated with a 52% increase in mortality risk (95% CI: 1.05-2.18) in a fully adjusted model. CONCLUSION: In community-dwelling adults aged ≥65 years, abdominal obesity was strongly associated with increased mortality risk. Being overweight appeared, however, to be protective against mortality. Modest self-reported weight loss was not associated with all-cause mortality in community-dwelling older adults after adjusting for health and lifestyle factors. However, men reporting recent weight loss of more than 3 kg may be at increased risk. The findings of this study support the use of WC, rather than BMI, as a predictor of mortality risk in older adults.

The association of weight change and all-cause mortality in older adults: a systematic review and meta-analysis.

OBJECTIVE: there may be age-related differences in the impact of weight change on health. This study systematically reviewed the evidence on the relationship between weight change and all-cause mortality in adults aged 65 years and older. METHODS: MEDLINE, EMBASE and CINAHL were searched from inception to 11 June 2020, PROSPERO CRD 42019142268. We included observational studies reporting on the association between weight change and all-cause mortality in older community-dwelling adults. A random-effects meta-analysis was performed to calculate pooled hazard ratios and scored based on the Agency for Healthcare Research and Quality guidelines. RESULTS: a total of 30 studies, including 1,219,279 participants with 69,255 deaths, demonstrated that weight loss was associated with a 59% increase in mortality risk (hazard ratio (HR): 1.59; 95% confidence interval (CI): 1.45-1.74; P < 0.001). Twenty-seven studies that reported outcomes for weight gain (1,210,116 participants with 65,481 deaths) indicated that weight gain was associated with a 10% increase in all-cause mortality (HR: 1.10; 95%CI: 1.02, 1.17; P = 0.01). Four studies investigated weight fluctuation (2,283 events among 6,901 participants), which was associated with a 63% increased mortality risk (HR: 1.66; 95%CI: 1.28, 2.15). No evidence of publication bias was observed (all P > 0.05). CONCLUSION: for community-dwelling older adults, weight changes (weight loss, gain or weight fluctuation) are associated with an increased risk of all-cause mortality risk relative to stable weight. Further research is needed to determine whether these associations vary depending upon initial weight, and whether or not the weight loss/gain was intentional.