An article in the current issue of the Journal Blood Advances discusses the impact of diabetes on the survival of patients with multiple myeloma in different racial groups.

Past research has shown that patients with multiple myeloma and diabetes have poorer survival outcomes compared to myeloma patients without diabetes.

The above-referenced paper is the first, however, to analyze and report on the difference in outcomes between white versus black patients with both myeloma and type 2 diabetes.

The study included over 5,000 myeloma patients, 15 % of whom had type 2 diabetes. The incidence rate of patients with both conditions showed that black patients were twice as prevalent as white patients. There are some very interesting conclusions from this study :

• There is a marked difference in overall survival (OS) in white patients with and without diabetes. Interestingly, this is not the case for black patients (i.e., overall survival is very similar regardless of whether the patient is or is not diabetic).
• “The prevalence of DM increased in both Black and White patients with higher Body Mass Index (BMI) categories and advancing age.” 
• “The prevalence of diabetes was almost as high in Black patients with normal weight (19%), as in White patients with obesity (21%), and almost a third of Black patients (32%) with obesity had diabetes.” 
• “Diabetes affected 20% of Black patients between 45 and 60 years of age, far exceeding the prevalence of diabetes in White patients aged >60 years of age (14%). These results show that diabetes is much more prevalent in Black MM patients compared to White patients, and disproportionately affects younger and normal weight Black patients with MM.”
• Interesting AND unexpected was this conclusion: “[For the total patient pool with both MM and diabetes] Elevated BMI was associated with improved OS … compared to normal weight. Underweight patients had similar OS to normal-weight patients. When analyzed by race, elevated BMI was protective in Black patients but not in White patients.” [emphasis added]

The authors of the study clearly state that “The underlying basis for increased incidence of myeloma in Black patients is not known. Unique [factors] in Black individuals have not been identified, suggesting factors beyond genetics, including diabetes and obesity, may be contributing, given that they affect the Black population to a greater degree than in the White population. In our study, we saw twice the prevalence of diabetes in the Black population compared to the White population with MM. The higher prevalence of myeloma in patients with diabetes suggests that diabetes may be a risk factor contributing to the increased development of MM in Black individuals compared to White individuals.” [emphasis added]

The authors also studied the impact of diabetes on myeloma growth in “special” diabetic and non-diabetic mice. This separate study showed that “Tumors grew in more of the [diabetic] mice compared with control [non-diabetic mice] and grew more rapidly in the [diabetic] mice compared with [non-diabetic] controls.” This shows that diabetes affects survival and risk of multiple myeloma cancer.

The authors conclude their paper with the observation and recommendation, “As patients with MM live longer than ever before given a rapidly changing treatment landscape due to the approval of novel therapies, inadequate diabetes management can lead to delays in diagnostic tests and the initiation of treatments, higher risks of complications from treatments, and deaths from cancer and non-cancer causes. Our data suggests that to further improve OS in our patients with MM, modifiable risk factors such as diabetes can no longer be ignored as we improve the chemotherapeutic management of this common hematological neoplasm. Pharmacological and non-pharmacological measures such as dietary intervention need to be investigated in future studies to improve outcomes in myeloma.” [emphasis added]