October 11, 2012
In an earlier CATIE News story we reported on a relatively large observational study from Denmark that did not find an increased risk for type 2 diabetes in a population that was mostly male and white. However, other populations, particularly people of colour, are generally at increased risk for the development of type 2 diabetes as they age.
Researchers across the U.S. have been studying a possible link between HIV infection and an increased risk for the development of type 2 diabetes among HIV-positive women and women who are at high risk for HIV infection. Their study of 2,051 women found an increased risk for type 2 diabetes among HIV-positive women. However, the researchers stressed that traditional risk factors for diabetes -- being overweight, older age and having close family members with type 2 diabetes -- also increased the risk for developing this condition. An advantage of the U.S. study is that it included women from different ethno-racial groups.
The Women's Interagency HIV Study (WIHS, pronounced "wise") has been collecting health-related information on women at high risk for and who have HIV infection for several decades. WIHS study sites are located in the following cities:
Every six months, participants receive a comprehensive physical examination, are interviewed by researchers and provide blood and other fluids for analysis.
Between October 2000 and March 2006, hemoglobin A1C (HbA1c or simply A1C) was assessed in blood tests. This test is sometimes useful, as it gives an average of a persons blood sugar levels over the past four months. Higher-than-normal A1C levels are associated with diabetes.
In this study, data was collected from 2,051 women who had fasting blood sugar, A1C and other available test results. Their HIV infection status was as follows:
The researchers used a complex set of rules to screen blood sugar measurements and information from medical charts (whether or not the person was using medicines to treat diabetes) to determine who had diabetes. For blood sugar measurements, they examined data from women whose blood sugar was 126 mg/dL (equivalent to 7 nmol/L) or greater. This level of blood sugar, if confirmed on repeated testing, indicates that type 2 diabetes has occurred.
The average profile of the HIV-positive women in the study was as follows:
Overall, HIV-positive women had a 40% higher relative risk for developing type 2 diabetes than HIV-negative women.
HIV-positive women who were 45 years or older had a three-fold increased relative risk for developing diabetes compared to HIV-positive women 35 or younger.
As mentioned previously, BMI is a relative indicator of fatness. People with a BMI between 18.5 and 25 may have an ideal body weight. People with a BMI less than 18 are considered underweight and people with a BMI between 25 and 30 are likely overweight. People with a BMI greater than 30 are considered obese. In the present study, women whose BMI was 40 (highly suggestive of serious obesity) or greater had a nearly four-fold increased relative risk of developing type 2 diabetes.
HIV-positive women with a BMI between 30 and 40 had about a three-fold increased relative risk for developing type 2 diabetes.
HIV-positive women who had a mother, father, brother or sister with type 2 diabetes had at least a 50% relative risk for developing this problem.
The research team found only a modest association between a woman being HCV positive and the subsequent development of type 2 diabetes.
The research team also examined possible associations between the use of ART and the risk of developing type 2 diabetes. There was a suggestion that ART users had an increased risk for developing type 2 diabetes. However, this finding is not robust. A different study with a different design must be carried out so that researchers can accurately assess the potential impact of HIV medicines on the risk for developing type 2 diabetes.
The latest WIHS report suggests that HIV infection is associated with an increased relative risk for the development of type 2 diabetes in HIV-positive women. However, they stated, "traditional risk factors including older age, obesity and family history [of type 2 diabetes] were strongly associated with [the future risk for developing] type 2 diabetes." The strengths of the WIHS study were that it monitored women for several years and it had women from a few different ethno-racial groups.
Studies have found that eating a healthy diet, exercising, modest weight loss and use of the insulin-sensitizing drug metformin (Glucophage) can significantly reduce the risk for developing type 2 diabetes. These interventions can work regardless of gender, age and ethnicity. Moreover, these changes also improve overall health.