Discussion
obesity, infection, weight loss, metabolic syndrome
OBESITY, DISEASE, EVENT, VIRAL INFECTION, INFECTION, ADIPOSITY, METABOLIC SYNDROME, DISEASES
We prospectively investigated, the association of baseline adiposity indices and their changes over time with the risk of a SARS-CoV2 infection in the PREDIMED-Plus cohort of older adults with overweight/obesity and metabolic syndrome. Expectedly, several baseline adiposity parameters measured 5–6 years prior to the pandemic were positively associated with COVID-19 risk. In addition, while decreases in body weight and BMI during this period were associated with decreased risk of COVID-19, even when adjusted for baseline values, reductions in girth measures were not associated with significant protective effect against COVID-19.Previously, several cross-sectional examinations from the early phase of the pandemic found that older adults and those with excessive body weight were typically more vulnerable to severe infection [Given the health consequences of excess body weight, it is universally recommended that those with overweight/obesity lose weight. However, there is scant information on the effect of the body weight trajectory of individuals in the period prior to COVID-19 on the disease risk, specifically in older adults. The findings from the current analysis suggest the importance of body weight loss in older adults with overweight and obesity, for improving resistance to viral infections such as COVID-19. These results are specifically useful given the expected increase in the emergence and transmission of zoonotic diseases [The inclusion of ABSI is a unique feature of this analysis that facilitates evaluating baseline or changes in central obesity independent of weight and height parameters (Supplementary Figure S1, Additional File In this context of our study findings, the recent highlight on the need to monitor and investigate weight loss in older adults aged over 65 years by the ASPREE trial is informative [This is one of the first studies to investigate in older adults with overweight/obesity and metabolic syndrome the longitudinal association of baseline anthropometric measures and their changes in 5–6 years prior to the COVID-19 pandemic with the risk of infection. The strength of the analysis lies in its large sample size and documentation of exposures and several confounder variables repeatedly with standardized techniques for a considerable duration before the pandemic. This facilitates the evaluation of the longitudinal association of baseline and changes in adiposity indices with COVID-19 risk while adjusting for several potential confounders, including participant location. Additionally, the duration of follow-up across categories of weight loss is comparable, negating the time-dependent effects of the intervention. Moreover, COVID-19 event adjudication was performed by an independent committee removing any potential bias in the ascertainment of cases. We have also used several adiposity indices including body weight, BMI, waist circumference, and WHtR to define the exposure. This is specifically useful to describe features of general and central obesity and identify differences, if any, in their association with COVID-19 risk.We also acknowledge the following limitations to this analysis. First, the small number of COVID-19 cases could have lowered the power of the study to identify associations of small magnitude. However, the incidence rate of COVID-19 in this study was similar to the national data reported for the time [