A View of Type 2 Diabetes as Accelerated Aging
The mortality characteristics resulting from type 2 diabetes look very much like an accelerated form of normal aging, as noted in today's open access paper reporting on a large epidemiological study. This mortality characteristic is so much like aging that at times in the past researchers have used animal models of type 2 diabetes as stand-ins for aging, in order to conduct studies more rapidly. Type 2 diabetes is a metabolic disease, a condition that usually arises from excess fat tissue, and is characterized by chronic inflammation, excessive blood sugar, high levels of circulating advanced glycation end-products, and other disruptive influences resulting from too much fat in the body, a state of hyperlipidemia.
In some senses being overweight is a form of accelerated aging: it results in a greater burden of senescent cells, for example. Mammals have evolved the capacity to become fat, but not to operate well over the long term while being fat. Perhaps the most important thing to note about type 2 diabetes is that it is reversible even in its late stages; type 2 diabetes is in a sense actively maintained by the presence of excess fat tissue. Sustained low calorie diets and weight loss have been shown to profoundly reverse type 2 diabetes in human clinical trials.
Mortality of type 2 diabetes in Germany: additional insights from Gompertz models
The Gompertz law of mortality proclaims that human mortality rates in middle to old ages grow log-linearly with age and this law has been confirmed at multiple instances. We investigated if diabetes mortality in Germany also obeys the Gompertz law and how this information helps to communicate diabetes mortality more intuitively.
We analyzed all statutory health-insured persons in Germany in 2013 that were aged 30 years or older. Deaths in 2014 were recorded and given in 5-year age groups. The study population consisted of 47,365,120 individuals, 6,541,181 of them with diabetes. In 2014, 763,228 deaths were recorded, among them 288,515 with diabetes. We fitted weighted linear regression models (separately for females and males and for people with and without diabetes) and additionally computed the probability that a person with diabetes dies before a person of the same age and sex without diabetes, and the "diabetes age", that is, the additional years of mortality risk added to an individual's chronological age due to diabetes-related excess mortality.
We found that diabetes mortality for females and males aged 30 years or older in Germany in 2014 followed the Gompertz law of mortality. The survival information of the population with diabetes during a large part of the lifespan can thus be reduced to the two parameters of the Gompertz distribution. In addition, the Gompertz distribution gives better fits than two competing, mechanistically also plausible distributions for the age at death. The probability that a female/male with diabetes dies before a female/male without diabetes (and the same age) is 61.9%/63.3%.