The Helicobacter pylori bacteria, which has previously been suspected of playing a role in the development of Type 2 diabetes, has been linked to impaired blood glucose control in adults in a study recently published in The Journal of Infectious Disease.
Helicobacter pylori, or H. pylori, is a type of bacteria that lives in the mucous lining of the stomach, where it may exist for decades. The bug, which is typically acquired before age 10, is usually passed between family members and contributes to the development of both stomach ulcers and stomach cancer. Roughly half of the world’s population is thought to be infected.
A number of studies have looked at the possible role of H. pylori in diabetes. For this study, researchers at the NYU Langone Medical Center sought to determine the association between the bacteria and HbA1c (also known as A1C), a marker of blood glucose control over the previous 2 to 3 months.
The researchers looked at data from 7,417 participants in the National Health and Nutrition Examination Surveys (NHANES) III and 6,072 participants in NHANES 1999–2000 who had data on file regarding H. pylori, HbA1c, and lifestyle and sociodemographic factors.
The researchers did not find any association between H. pylori and a self-reported history of diabetes. However, after excluding people with diabetes and adjusting for various factors, they found that colonization by H. pylori was associated with higher A1C levels; in the NHANES 1990–2000 study, the 2,403 people who were H. pylori-positive had an average A1C level of 5.49%, while the 3,669 without H. pylori had an average A1C of 5.40%.
The association was even stronger among those who had a body-mass index of 25 or higher (a body-mass index of 25 to 29.9 is considered overweight, while a BMI of 30 or over is considered obese): The increase in A1C associated with having both a higher body-mass index and H. pylori was greater than the increase in A1C would be if it were the sum of the two circumstances occurring individually.
According to study coauthor Martin J. Blaser, MD, “Obesity is an established risk factor for diabetes and it is known that high BMI is associated with elevated HbA1c. Separately, the presence of H. pylori is also associated with elevated HbA1c. We hypothesized that having both high BMI and the presence of H. pylori would have a synergistic effect, increasing HbA1c even more than the sum of the individual effect of either risk factor alone. We now know that this is true.”
The researchers suspect that the bacteria may affect the levels of two hormones in the stomach that help regulate blood glucose levels, and suggest that eliminating H. pylori using antibiotics in some older, obese individuals may have health benefits. They also note that further studies are needed to determine the effects of the bacteria — and of the removal of the bacteria — in different age groups and in people with varying body-mass indices.
To learn more about the research, read the article “H. Pylori Bacteria Linked to Blood Sugar Control in Adult Type II Diabetes” or see the study’s abstract in The Journal of Infectious Disease.