Virtually all organ systems are impaired in the face of diabetes.
To say that diabetes is a public health problem is an understatement.
According to the American Diabetes Association, an estimated 25.8 million men, women and children in the United States have diabetes (2011 Data). That’s an astounding 8.3% of the nation’s population, roughly the population of Texas! It includes the nearly 19 million diagnosed cases and about 7 million with undiagnosed disease. To put this in perspective, in 1990 about 6.5 million US adults had diagnosed diabetes, in 2000, that number had nearly doubled, and in 2010, the figure was nearly 21 million.
While diabetes is a disorder of glucose metabolism, very few individuals die from hyperglycemic crisis. The real cost of the disease, both in financial and physiologic terms, comes from complications that attend uncontrolled or poorly controlled glycemia. Virtually all organ systems are impaired in the face of diabetes. Cardiovascular disease, renal impairment, neuropathy, ocular changes, alterations in immune function, and impaired wound healing are part and parcel of long-standing diabetes, sometimes even in the presence of reasonably well-controlled blood glucose. To complicate matters, some therapies that provide good glycemic control have adverse effects on the musculoskeletal system.
As you can imagine, all of this comes with a huge price tag. The total cost to the US to treat diagnosed diabetes in 2012 was US$245 billion! This number includes direct medical costs ($176 billion) as well as $69 billion in lost productivity and inability to work.
There is, however, solid evidence that some of these problems can be managed effectively. The Diabetes Control and Complications Trial, a large clinical trial funded by the US National Institutes of Health from 1983 through 1993 demonstrated that aggressive control of blood glucose slowed the onset and progression of ocular, renal and nerve damage in Type 1 diabetic patients. And a study published in April in the New England Journal of Medicine that examined changes in diabetes complications in the US from 1990 through 2010 found further reasons to be optimistic about the state of diabetes in the US.
Federal researchers from the US Centers for Disease Control and Prevention collected data from a number of sources to compare the incidences of stroke, cardiovascular disease (CVD), lower extremity amputation, end stage renal disease, and death from hyperglycemic over the indicated 20-year time interval. They discovered that relative rates of complications decreased for all of these categories, with the largest declines observed for CVD and death from hyperglycemic crisis. While the nationwide rate of CVD has decreased in the general population, rate reductions were greater in adults with diabetes than in those without diabetes.
The bad news here is that when the data are expressed as rates for the overall population (which takes into account an increase in the prevalence of diabetes) there were no reductions in the rates of amputation, stroke or end-stage renal disease.
There is no doubt that we have made inroads into treating the many complications of diabetes. Some of the progress made is due to improved treatments in glycemic control and insulin sensitization. Improved ancillary treatments for hypercholesterolemia and hypertension have also helped.
But there is a lot of room for improvement. The incidence of diabetes has doubled in the past 15 years, and the prevalence has tripled as mortality has declined. As the population ages it approaches the age range that is characterized by a high incidence of diabetes, which is the harbinger of an increase in the total burden or absolute number of complications. Little has been studied with respect to ocular or skeletal health. Progress is being made against CVD, especially in diabetics, but these problems are still major public health issues.
The articles appearing over the next several days will highlight some of the areas that we can address experimentally to make inroads against diabetic complications, and to understand what the cost of those treatments will be in terms of pathophysiologic capital.
Our insight into how to prevent or manage diabetic complications holds the promise that reduction in the burden of this global epidemic can be reduced.