Note: The following is a guest blog by Dr Aus Alzaid, a practicing physician caring for people with diabetes in Saudi Arabia. Dr Alzaid can be contacted via LinkedIn. If you too have had problems accessing clinical trial results and would like to share your story, please contact the AllTrials team.

Aus Alzaid pic

Many of my patients suffer from diabetes, and because of the commonly observed link between diabetes and Alzheimer’s disease, I recently decided to examine the medical literature to see if any of the medications used to treat diabetes affected memory or caused dementia. I could find nothing sinister about the diabetes agents I looked at; if anything, some seemed to hold future promise as agents against dementia.

However, I was struck by the evidence on one diabetes drug called metformin. The results seemed conflicting, with some studies showing a higher risk of dementia while others reporting exactly the opposite. The fact that the verdict on metformin was uncertain was somewhat unsettling for me – I didn’t want to give my patients anything to lower blood sugar if it meant them losing their minds too!

Metformin is an extremely popular and effective diabetes therapy that has been with us for many years without undue medical concerns. The scientific evidence on metformin and dementia however, was limited to laboratory data and crude observational surveys. To settle the issue properly, one needed to find randomized placebo-controlled clinical trials undertaken to address this specific question. Luckily, I managed to find one such study, which had been started in 2008 and completed in 2012. The lead investigator had indicated on the record that the outcome of the study would be reported in 2012. However, I searched everywhere for information about this study without success.

There could be many reasons why a study would be delayed or left unpublished, but the public needs to know about the fate of the study at some point in time. In the case of the trial on metformin discussed here, it had been almost four years since the work was completed and there was still no news on the results.

In the meantime, millions of people were taking the drug and could be at risk of dementia unless the work was published. So I contacted the main investigator directly asking for information about the study. Regrettably, repeated emails did not elicit a reply. (Someone from the AllTrials campaign later contacted the same person and received a response within days.)

The paper describing the trial was finally published earlier this year. Fortunately, the work published showed no mental harm to patients taking metformin. On the contrary, the investigators described an improvement in cognitive tests in some of the patients studied. This result gives myself, and everyone else involved in the care of people with diabetes, some peace of mind next time we prescribe metformin or see someone take this medication.

However, I kept wondering to myself what could have happened if metformin had shown the opposite effect in that trial. In that case, doctors like myself would have continued prescribing the drug for all the years the trial was left unpublished, potentially and unknowingly exposing millions of patients to the risk of mental decline.

Such a state of affairs should not be allowed to happen again: it should not be left to a random physician or a private individual to chase after the results of clinical trials or personally plead with investigators to publish their finished work. Publication of registered clinical trials is a professional responsibility, not a personal prerogative of the main investigator. This fact is clearly stated in all professional codes of conduct. Non-publication without justifiable reasons is blatant ethical and research misconduct.

Finally, I look forward to the day of seeing effective sanctions on all those who fail to comply with their obligations. This is a cause worthy of all our support as doctors and patients.