Obesity Considerably Raises the Risk of Later Life Frailty
As might be expected, epidemiological data shows that obesity in mid-life raises the risk of suffering frailty in later life. Excess visceral fat tissue increases the pace at which senescent cells accumulate in the body and generates chronic inflammation, disruptive of tissue structure and function. In that sense it literally accelerates aging and the onset of age-related conditions, particularly those known to be driven in large part by chronic inflammation.
The present study followed 4,509 community-dwelling participants from the population-based Tromsø study from 1994 to 2016 to examine the association between general and abdominal obesity and the risk of frailty. This study suggests an increased likelihood of pre-frailty/frailty among those with baseline obesity. Increased likelihood of pre-frailty/frailty was also observed among those with high or moderately high waist circumference (WC) at baseline.
Participants with baseline obesity (adjusted odds ratio [OR] 2.41), assessed by body mass index (BMI), were more likely to be pre-frail/frail than those with normal BMI. Participants with high (OR 2.14) or moderately high (OR 1.57) baseline WC were more likely to be pre-frail/frail than those with normal WC. Participants in the 'overweight to obesity' or the 'increasing obesity' trajectories had increased odds of pre-frailty/frailty compared with those in the stable normal BMI trajectory. Additionally, participants with a high WC at baseline, whose WC gradually or steeply increased throughout the follow-up period, had increased odds of being pre-frail/frail compared with those in a stable normal WC trajectory.
There are different mechanisms through which obesity might contribute to pre-frailty/frailty. Increased adiposity leads to increased secretion of pro-inflammatory adipokines, thus contributing to inflammation, which is also associated with frailty among older adults. Obesity leads to increased fat mass and increased lipid infiltration in muscle fibres resulting in reduced muscle strength and function. When coupled with an age-related decline in muscle mass and strength, it causes 'sarcopenic obesity', which is linked to an increased risk of frailty and disability.