Four years of non-diabetic status after diagnosis of impaired glucose tolerance reduces cardiovascular risks

In a recent study published in the journal PLoS Medicinea group of researchers in China examined whether the years a person maintained non-diabetic status after an initial diagnosis of impaired glucose tolerance (IGT) was associated with the risk of long-term outcomes such as cardiovascular disease or death.

Study: Non-diabetic status after diagnosis of impaired glucose tolerance and risk of long-term death and vascular complications: A retrospective analysis of the Da Qing Diabetes Prevention Outcome Study. Image credit: siam.pukkato / Shutterstock

Record

Type 2 diabetes is rapidly becoming a global health concern, especially because it increases the risk of cardiovascular disease, disability and mortality, and exerts a significant economic burden on patients and societies. However, among people diagnosed early with impaired glucose tolerance, interventions related to lifestyle changes, such as increased exercise and dietary modifications, have been found to be effective in delaying the progression of diabetes.

Studies by the American Diabetes Association have shown that lifestyle modifications significantly reduce the risk of cardiovascular disease, microvascular complications, and all-cause mortality. However, other studies have reported that lifestyle interventions and metformin therapy did not reduce the risk of CVD.

Furthermore, the number of years a person maintained nondiabetic status after a diagnosis of impaired glucose tolerance due to lifestyle interventions and its association with the risk of long-term outcomes such as cardiovascular risk and all-cause mortality remain unclear.

About the study

In the present study, researchers analyzed post hoc data from the Da Qing Diabetes Prevention Study (DQDPS), a six-year lifestyle intervention trial among people diagnosed with impaired glucose tolerance.

Here, researchers used data on 540 people enrolled in the DQDPS to determine the long-term risk of macro- and microvascular disease and nondiabetic-related mortality at two, four, and six years after diagnosis of impaired glucose tolerance.

The original study, DQDPS, enrolled people diagnosed with impaired glucose tolerance using an oral glucose tolerance test and conducted an intervention involving lifestyle modifications, with medical assessments performed every two years to determine any change in non-diabetic status.

Those who remained nondiabetic at each two-year assessment were asked to continue the lifestyle intervention. The lifestyle intervention was discontinued for patients with diabetes during any of the assessments.

Long-term outcomes examined in the present study included the risk of cardiovascular disease, including fatal and nonfatal stroke, heart failure, and coronary heart disease, including fatal or nonfatal myocardial infarction. Composite microvascular disease was also one of the outcomes examined and was defined as the combined outcome of neuropathy, nephropathy and retinopathy.

Retinopathy included proliferative retinopathy, photocoagulation, or blindness associated with retinal disease. A wide range of kidney-related diseases, such as renal clearance, end-stage renal disease, kidney transplantation, or CKD-related death, were included in nephropathy. Neuropathy consists of ulceration, gangrene formation in the leg, ankle or foot, or amputation.

To assess cardiovascular death rates, researchers used standardized questionnaire-based interviews with relatives and death certificates or medical records to verify cause of death. A post hoc statistical analysis was performed to determine the association between duration of nondiabetic status and the risk of long-term clinical outcomes.

Results

The study found that maintaining a non-diabetic status for several years after a diagnosis of impaired glucose tolerance was associated with a significantly lower risk of cardiovascular complications or mortality. Furthermore, maintaining nondiabetic status for even four years significantly improved the risk of long-term clinical outcomes.

People who managed to maintain their non-diabetic status for at least four years had a 26% reduction in their 30-year risk of macrovascular complications and a 37% and 38% reduction in the risk of microvascular complications and all-cause mortality, respectively. . In addition, the risk of cardiovascular disease-related mortality was found to be significantly lower in people who remained non-diabetic for six years after being diagnosed with impaired glucose tolerance.

These findings suggest that for individuals at high risk of developing diabetes who were diagnosed with impaired glucose tolerance, there was a four-year time limit for implementing lifestyle interventions and maintaining non-diabetic status, which could affect important long-term results. such as cardiovascular disease and mortality. Exceeding this four-year mark could further improve survival and reduce the long-term risk of complications and death.

conclusions

In summary, researchers conducted a retrospective analysis of data from a long-term lifestyle intervention trial conducted in people diagnosed with impaired glucose tolerance to determine whether the duration of nondiabetic status had an impact on reducing risk of cardiovascular disease or mortality.

The findings suggest that if non-diabetic status was maintained for at least four years, people at high risk of diabetes had a significantly lower risk of macro- and microvascular complications and cardiovascular disease-related mortality. Longer periods of remaining diabetes-free further improved survival rates and reduced the risk of cardiovascular complications.