H. Pylori Bacteria Linked to Elevated A1C

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.

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  • Joe

    I have always suspected that metabolic syndrome, especially in people who find it nearly impossible to lose weight despite strict dieting and vigerous exercise, had biological cause.

    Interesting too is the fact that the only time I was able to lose weight easily was after open heart surgery, when I was pumped full of megadoses of antibiotics. Despite the fact that my ability to exercise was severely limited, the pounds just fell off.

  • Muriel McGrann RN

    Cure??? How diagnosed local labs??? name of test?? Thankyou

  • Diane Fennell

    Hi Ms. McGrann,

    Thanks for your questions. An H. pylori infection can be cured with antibiotics, and the presence of this bacteria can be checked for with a blood test, a urea breath test, or a stool antigen test (more information on those tests can be found here).

    It is worth noting, however, that this study did not come to any conclusions about whether people with H. pylori should be treated with antibiotics: Further research is necessary to determine how the bacteria affect different groups of people and just what the effects would be of removing the bacteria in various populations. If you have any questions about your situation, be sure to speak with your health-care provider.

    Thanks for your interest in Diabetes Self-Management!

    Diane Fennell
    Web Editor

  • Linda

    Interesting article but is it something that you could do something about? Sometimes it’s just a touch of something to get your interest up?
    Is this one of those or should we follow up with the tests to check it out?

  • Janet

    I have type 2, take insulin and found out I also have H. pylori, took some antibio’s but they never gave me a test to tell me if it was ok or not,I go back to Dr. 3/26 and will take a copy of this with me! I was always so skinny till I was about 33 after my last child was born, and have the hardest time losing it. I stopped taking my insulin and lost 15 lbs in a month, but paid for it! now I have to take more and the lb’s came right back on. Is there any studies coming up? I volunteer

  • Diane Fennell

    Hi Linda,

    Thanks for your comment. This was preliminary research that was limited by a number of factors, so scientists will have to do further studies before determining how to proceed with this information (including whether or not to make any recommendations about treating H. pylori for blood glucose control). In the meantime, if you have any concerns about your situation, I’d encourage you to speak with your health-care provider.

    Thank you for your interest in DiabetesSelfManagement.com!

    Diane Fennell
    Web Editor

  • Diane Fennell

    Hi Janet,

    Thanks for your comment. You can do a search on Web sites such as ClinicalConnection.com and ClinicalTrials.gov to see if any studies on H. pylori and diabetes are currently recruiting in your area.

    Diane Fennell
    Web Editor

  • mary

    This study did not include diabetics. If I read it correctly, it specifically eliminated anyone with a known history of diabetes.