High Blood Sugar Linked to Cardiovascular Diseases

High blood sugar levels may increase the risk for cardiovascular diseases, especially in women, a study finds.

Even moderately elevated levels are associated with a 30-50% higher risk of developing heart and circulatory problems, according to a study published in The Lancet Regional Health Europe.

The study, led by researchers at the London School of Hygiene & Tropical Medicine (LSHTM) and University College London (UCL), looked at U.K. Biobank data from 427,435 adults aged 40 to 69 across the glycaemic spectrum, such as people with blood sugar levels within a "normal" range, those with prediabetes, and those with type 2 diabetes.

Among those within the "normal" range of blood sugar, the lower levels appear to be better at protecting against cardiovascular diseases (CVDs). For example, those with the lowest levels were 10% less likely to develop any form of CVD than others in this group.

Men with raised blood sugar below the threshold for diabetes had a 30% greater risk of developing CVDs, compared to a 30% to 50% risk for women. In those with diagnosed diabetes, the risks doubled.

The differences in the relative risk of developing CVDs between men and women largely disappeared after the researchers accounted for measures of obesity and the use of antihypertensive and statin therapies, drugs that reduce cholesterol levels.

However, the researchers discovered that men are more often prescribed antihypertensive and statin therapies than women, even if they have similar blood sugar levels. Although the reasons are unclear, some studies show that it is common for men and women to receive different treatment at a doctor’s office.

The research findings indicate that people with prediabetes are at a significantly increased risk for developing cardiovascular diseases. About 96 million people in the United States have prediabetes, a condition where blood sugar levels are raised but not high enough to be diagnosed as type 2 diabetes. A recent study suggests that 1 in 5 American adults deemed healthy may have a pre-diabetic glucose metabolism pattern.

Our results suggest that the increased risks seen in both men and women could be mitigated through modifiable factors, including weight reduction strategies and greater use of antihypertensive and statin medications. This is an important new insight that should help guide future public health strategies.

- Senior author Professor Krishnan Bhaskaran from LSHTM

The findings cannot be applied to type 1 diabetes as people with the condition weren’t included in the study. When it comes to type 2 diabetes, the findings also have to be generalized with caution because the U.K. Biobank participants are healthier than the overall population in the United Kingdom, and lifestyle data were self-reported.

Abigail Dove, a Ph.D. student at Karolinska Institute in Sweden who is not involved in the study, says the findings could suggest a need for more intensive risk factor control once prediabetes is diagnosed.

"The study also showed particularly elevated CVD risk for people with undiagnosed diabetes, which underscores the need for greater screening for diabetes so glucose-lowering medications and lifestyle modifications can be initiated sooner, to reduce the risk of CVD in this high-risk group," she told Healthnews.

According to Dove, the threshold for "normal" blood sugar was originally defined as the point at which there is an elevated risk for diabetes-related retinopathy, a microvascular diabetes complication.

"It seems that the HbA1c (blood sugar) threshold for elevated risk of CVD, a macrovascular complication, may be lower, but additional studies are needed to confirm that," she adds.

High blood sugar levels are primarily associated with the increased risk of diabetes, a chronic condition that can harm the eyes, kidneys, nerves, heart, and blood vessels.

You may have elevated blood sugar levels if you experience fatigue, thirst, blurry vision, and the need to urinate more often.

The other ways to manage blood sugar levels, according to the CDC may include:

• Regular exercise. Adults should aim for 150 minutes per week of moderate-intensity aerobic activity or 75 minutes per week of vigorous aerobic activity.
• Eating at regular times and not skipping meals. Choose foods lower in calories, saturated fat, trans fat, sugar, and salt.
• Drinking water instead of juice or soda and limiting alcohol intake.
• Choosing fruit for the dessert.

The study underlines the importance of keeping blood sugar levels within the normal range to prevent not only diabetes but also cardiovascular diseases.