Body Mass Index, Change in Body Mass Index, and Survival in Old and Very Old Persons

Abstract

Background Current recommendations from the World Health Organization (WHO) are that individuals should seek to maintain a body mass index (BMI) between 18.5–25 kg/m2, independent of age. However, there is an ongoing discussion whether the WHO recommendations apply to old (70 ≥ 80 years) and very old persons (80+ years). In the present study we examine how BMI status and change in BMI are associated with mortality among old and very old individuals. Design Pooled data from three multidisciplinary prospective population-based studies OCTO-twin, GENDER, and NONA. Setting Sweden. Participants 882 individuals aged 70 to 95 years. Measurements Body Mass Index was calculated from measured height and weight as kg/m2. Information about survival status and time of death was obtained from Swedish Civil Registration System Results Mortality hazard was 20% lower for the overweight group relative to the normal/underweight group (RR = 0.80, p< .05), and the mortality hazard for the obese group did not differ significantly from the normal/underweight group (RR = 0.93, > .10), independent of age, education, and multimorbidity. Furthermore, mortality hazard was 65% higher for the BMI loss group than for the BMI stable group (RR = 1.65, p< .001) and 53% higher for the BMI gain group than for the BMI stable group (RR = 1.53, p≤ .001). However, the BMI change differences were moderated by age, i.e., the higher mortality risks associated with both loss in BMI and BMI gain were less severe in very old age. Conclusion Old persons who were overweight had a decreased mortality risk compared to old persons having a BMI below 25, even after controlling for weight change and multimorbidity. Compared to persons who had a stable BMI those who increased or decreased in BMI had a higher mortality risk, particularly among people aged 70 to 80. This study lends further support for the opinion that the WHO guidelines are overly restrictive in old age.

Effect of weight loss on mortality in overweight and obese nursing home residents during a 5-year follow-up

“…3,4 On the other hand, several studies on older communitydwelling people showed that being overweight or mildly obese lowered the mortality risk by comparison with normal or underweight status. [5][6][7][8][9][10][11][12] This trend was confirmed by different studies in the NH setting, in which a lower mortality risk coincided with a higher body mass index (BMI). [13][14][15] Weight changes might have a key role in explaining the unexpected relationship between BMI and mortality in old people.…”

“…A low BMI may therefore simply be a symptom of disease-related weight loss, and the drop in BMI may be a better indicator of the related mortality risk. 7 Having said that, for individuals with a higher BMI, weight loss may have a beneficial effect on any osteoarthritis, diabetes or cardiovascular diseases. 17 Very little is known, however, about the effect of weight loss (also in relation to baseline BMI) on mortality in frail NH residents.…”

Body mass index in dementia

“…RE is typically described among populations with low life expectancies, in which the effects of traditional cardiovascular risk factors might not have time to materialize, representing competing hazards. 9,33 Furthermore, inflammation is an important component in all these conditions, and has also been linked to AD. 86 The malnutrition--inflammation complex syndrome was first described among terminal renal failure patients 32 but could also be applicable to other populations, such as heart failure, 36 and is a key factor in explaining RE observations.…”

“…5 Controversy exists over the BMI associated with lowest mortality among older individuals, which could lie at, or above, the overweight range of BMI as defined by the WHO (25-29.9 kg/m2). [6][7][8][9][10] The term 'obesity paradox' describes the phenomenon of excess weight presenting opposite effects on mortality risk in younger and older populations, 11 and parallels effects described with other cardiovascular risk factors in certain chronically ill populations. Most nutritional assessment tools use one BMI cut-off for all adult people; [12][13][14][15][16][17][18] however, higher cut-offs are suggested for older people.…”

Fat Matters: Understanding the Role of Adipose Tissue in Health in HIV Infection

“…A strong association between mortality and weight loss has been well-described among older, HIV-uninfected adults independent of underlying disease or comorbid illnesses [114-117]. One longitudinal study observed an increased risk of death among older adults (mean age 73) who experienced any appreciable weight loss after the age of 21 and among underweight older adults in the 3 rd -8 th decades of life [115].…”