Diabetes mellitus and risk of plasma cell and lymphoproliferative disorders in 94,579 cases and 368,348 matched controls

Dietary risk factors for monoclonal gammopathy of undetermined significance in a racially diverse population

ABSTRACT

Monoclonal gammopathy of undetermined significance (MGUS), a precursor of multiple myeloma, is associated with shorter lifespan and cardiac, renal, neurologic, and immune-related comorbidities. There is little known about modifiable risk factors for this condition. To determine whether the risk of MGUS is associated with dietary factors in a racially diverse population, we conducted a US population-based case-control study from the National Health and Nutrition Examination Survey (1988-2004), which included 373 individuals with MGUS and 1406 matched controls. Diet was characterized by one 24-hour dietary recall, with gram intake of individual foods and beverages aggregated into groups. Unconditional multivariable logistic regressions were used to model associations between intake of several food groups and MGUS, with odds ratios (ORs) and 95% confidence intervals (CIs) reported for the highest relative to the lowest quantile of intake. Daily gram intake of several food and beverage groups were significantly associated with MGUS. MGUS was inversely associated with whole-grain bread, oats, and rice (OR, 0.70; 95% CI, 0.48-1.00; P < .05), fruits (excluding juice) and vegetables (OR, 0.69; 95% CI, 0.52-0.93; P = .02), vegetables (OR, 0.75; 95% CI, 0.56-0.99; P < .05), tomatoes (OR, 0.72; 95% CI, 0.51-1.00; P < .05), and cruciferous vegetables (OR, 0.44; 95% CI, 0.26-0.74; P < .01). Direct associations were observed for sugar-sweetened beverages (OR, 1.34; 95% CI, 1.00-1.78; P < .05), sugar-sweetened soft drinks (OR, 1.41; 95% CI, 1.01-1.96; P = .04), and artificially sweetened soft drinks (OR, 1.55; 95% CI, 1.04-2.33; P = .03). Our study shows that diet is potentially a modifiable risk factor for MGUS.

Prevalence and impact of diabetes on survival of patients with multiple myeloma in different racial groups

ABSTRACT

Multiple myeloma (MM) is twice as common in Black individuals compared with in White individuals, and diabetes mellitus (DM) disproportionately affects Black patients. Although numerous studies have shown a correlation between DM and MM, this has not been studied in the context of race and in vivo mechanisms. We conducted a retrospective clinical study of 5383 patients with MM of which 15% had DM (White, 12% and Black, 25%). Multivariable Cox models showed reduced overall survival (OS) for patients with DM (hazard ratio, 1.27; 95% confidence interval, 1.11-1.47; P < .001). This appeared to be driven by a marked difference in OS between White patients with and without DM but not in Black patients. In contrast, obesity was associated with better OS in Black patients but not in White patients. To complement this analysis, we assessed MM growth in a genetically engineered immunocompromised nonobese diabetic (Rag1-/-/muscle creatinine kinase promoter expression of a human IGF1R [M] with a lysine [K] to arginine [R] point mutation) mouse model to evaluate the mechanisms linking DM and MM. MM.1S xenografts grew in more Rag1-/-/MKR mice and grew more rapidly in the Rag1-/-/MKR mice compared with in controls. Western blot analysis found that MM1.S xenografts from Rag1-/-/MKR mice had higher phosphorylated S6 ribosomal protein (Ser235/236) levels, indicating greater activation of the mammalian target of rapamycin pathway. Our study is, to our knowledge, the first to evaluate racial differences in DM prevalence and survival in MM, as well as the effect of DM on tumor growth in mouse models. Our results suggest that DM may contribute to the higher incidence of MM in Black patients; and to improve survival in MM, DM management cannot be ignored.

Monoclonal Gammopathy of Undetermined Cardiovascular Significance; Current Evidence and Novel Insights

Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant condition characterized by the presence of low levels of a monoclonal protein in the serum and a low percentage of clonal plasma cells in the bone marrow. MGUS may progress to multiple myeloma or other plasma cell disorders at a rate of 1% annually. However, MGUS may also have adverse effects on the cardiovascular system independent of its malignant potential. Emerging data have shown that MGUS is associated with cardiovascular disease. The mechanisms underlying this association are not fully understood but may involve genetic abnormalities, vascular calcification, cryoglobulinemia, cold agglutinin disease, autoantibodies and the direct or indirect effects of the monoclonal protein on the vascular endothelium. Herein, we review current evidence in this field and we suggest that patients with MGUS may benefit from regular cardiovascular risk assessment to prevent severe cardiovascular complications, in parallel with close hematological follow-up to monitor potential disease progression.

Obesity and myeloma: Clinical and mechanistic contributions to disease progression

Obesity and obesogenic behaviors are positively associated with both monoclonal gammopathy of unknown significance (MGUS) and multiple myeloma (MM). As the only known modifiable risk factor, this association has emerged as a new potential target for MM prevention, but little is known about the mechanistic relationship of body weight with MM progression. Here we summarize epidemiological correlations between weight, body composition, and the various stages of myeloma disease progression and treatments, as well as the current understanding of the molecular contributions of obesity-induced changes in myeloma cell phenotype and signaling. Finally, we outline groundwork for the future characterization of the relationship between body weight patterns, the bone marrow microenvironment, and MM pathogenesis in animal models, which have the potential to impact our understanding of disease pathogenesis and inform MM prevention messages.