An Example of a Pitfall in the Correlation of Excess Fat with Age-Related Disease

Terrible, slow moving age-related diseases that kill you also tend to make you lose weight along the way. Even the lengthy period of gradually increasing disability prior to full-blown disease can achieve that result. This point is very important to bear in mind when looking at association studies that map measures of weight versus disease risk, or life expectancy, or other health metrics. Are the studies using late snapshots of weight, or lifetime maximum weight, or some other measure and time, and does that choice of data succeed in avoiding entanglement with the loss of weight that serious age-related disease tends to produce? If it doesn't, then the result may be suspect. The study I'll point out today examines a very large set of data, that of more than a million individuals. In the course of processing this data, the study authors well illustrate the point made above. For measures of weight taken decades prior to the development of age-related disease, excess weight correlates with raised risk of disease. But if measuring weight within a few years of the diagnosis of age-related disease, that correlation is reversed - in later life, the group of normal weight people includes some of the least healthy, who have lost weight since their earlier highs due to the early stages of disease and dysfunction. They developed age-related disease because they were overweight, but then their status becomes less visible to simple statistics as the weight is lost. There is...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs