title: Reappraisal of risk factors for monoclonal gammopathy of undetermined significance.
abstract: A number of epidemiologic studies have demonstrated associations between obesity and diabetes and the risk of monoclonal gammopathy of undetermined significance (MGUS). However, since MGUS is an asymptomatic condition we evaluated whether these are true associations or the result of detection-bias. We conducted a nested case-control study using a large primary-care database. Cases were defined as those with incident diagnosis of MGUS. For every case, four eligible controls matched on age, sex, practice site, and duration of follow-up were selected. Exposure variables included obesity and diabetes (including antidiabetic therapies) as well as other metabolic risk factors. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using conditional logistic regression. The study included 2363 MGUS patients and 9193 matched controls. In the primary analysis, obesity and diabetes were associated with higher MGUS risk with an adjusted ORs of 1.15 (95% CI 1.02-1.29) and 1.30 (95% CI 1.13-1.50), respectively. However, after adjustment to the number of laboratory tests prior to the MGUS diagnosis, there was no association between obesity and diabetes and MGUS risk (ORs of 1.08, 95% CI 0.96-1.22 and 1.08, 95% CI 0.93-1.25, respectively). In an additional analysis of antidiabetic therapies and MGUS risk, there was a nonsignificant decrease in MGUS risk among diabetes patients treated with metformin alone compared to subjects without diabetes (OR 0.77, 95% CI 0.56-1.05). In summary, while previously described risk factors for MGUS might be the result of detection bias, metformin should be further evaluated as a possible chemoprevention modality. Am. J. Hematol. 91:581-584, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.|Abramson Cancer Center, University of Pennsylvania, Philadelphia, Pennsylvania.|Tel-Aviv University, Tel-Aviv, Israel.
authors.forename: Ben
authors.initials: B
authors.lastname: Boursi
authors.affiliation: Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.|Abramson Cancer Center, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Brendan M
authors.initials: BM
authors.lastname: Weiss
authors.affiliation: Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Kevin
authors.initials: K
authors.lastname: Haynes
authors.affiliation: Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.|Abramson Cancer Center, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Ronac
authors.initials: R
authors.lastname: Mamtani
authors.affiliation: Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Yu-Xiao
authors.initials: YX
authors.lastname: Yang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D003920:Diabetes Mellitus; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000009:adverse effects; D008297:Male; D008687:Metformin / Q000009:adverse effects; D008875:Middle Aged; D008998:Monoclonal Gammopathy of Undetermined Significance / Q000209:etiology*; D009765:Obesity; D012307:Risk Factors
chemical_list: D007004:Hypoglycemic Agents; D008687:Metformin