Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant clonal disorder that progresses to multiple myeloma (MM), or other plasma-cell or lymphoid disorders at a rate of 1%/year. We evaluate the contribution of body mass index (BMI) to MGUS progression beyond established clinical factors in a population-based study. We identified 594 MGUS through a population-based screening study in Olmsted County, Minnesota, between 1995 and 2003. Follow-up time was calculated from the date of MGUS to last follow-up, death, or progression to MM/another plasma-cell/lymphoid disorder. BMI (kg/m2 < 25/≥25) was measured close to screening date. We used Cox regression to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association of BMI ≥ 25 versus BMI < 25 with MGUS progression and also evaluated the corresponding c-statistic and 95% CI to describe discrimination of the model for MGUS progression. Median follow-up was 10.5 years (range:0–25), while 465 patients died and 57 progressed and developed MM (N = 39), AL amyloidosis (N = 8), lymphoma (N = 5), or Waldenstrom-macroglobulinemia (N = 5). In univariate analyses, BMI ≥ 25 (HR = 2.14,CI:1.05–4.36, P = 0.04), non-IgG (HR = 2.84, CI:1.68–4.80, P = 0.0001), high monoclonal (M) protein (HR = 2.57, CI:1.50–4.42, P = 0.001), and abnormal free light chain ratio (FLCr) (HR = 3.39, CI:1.98–5.82, P < 0.0001) were associated with increased risk of MGUS progression, and were independently associated in a multivariable model (c-statistic = 0.75, CI:0.68–0.82). The BMI association was stronger among females (HR = 3.55, CI:1.06–11.9, P = 0.04) vs. males (HR = 1.39, CI:0.57–3.36, P = 0.47), although the interaction between BMI and sex was not significant (P = 0.15). In conclusion, high BMI is a prognostic factor for MGUS progression, independent of isotype, M protein, and FLCr. This association may be stronger among females.
意义未明单克隆免疫球蛋白病（MGUS）是一种癌前克隆性疾病，以每年1%的速率进展为多发性骨髓瘤（MM）或其他浆细胞或淋巴系统疾病。我们通过一项基于人群的研究，评估了体质指数（BMI）在已知临床因素外对MGUS进展的影响。我们于1995年至2003年间在明尼苏达州奥姆斯特德县通过基于人群的筛查研究识别出594例MGUS患者。随访时间从MGUS确诊日期计算至末次随访、死亡或进展为MM/其他浆细胞/淋巴系统疾病。BMI（kg/m²＜25/≥25）的测量时间接近筛查日期。我们采用Cox回归分析评估BMI≥25与BMI＜25相比对MGUS进展的风险比（HR）和95%置信区间（CI），并通过计算相应的c统计量及95% CI来描述模型对MGUS进展的区分能力。中位随访时间为10.5年（范围：0-25年），期间465例患者死亡，57例进展并发展为MM（39例）、AL淀粉样变性（8例）、淋巴瘤（5例）或华氏巨球蛋白血症（5例）。单变量分析显示，BMI≥25（HR=2.14，CI：1.05-4.36，P=0.04）、非IgG型（HR=2.84，CI：1.68-4.80，P=0.0001）、高水平单克隆（M）蛋白（HR=2.57，CI：1.50-4.42，P=0.001）以及异常游离轻链比率（FLCr）（HR=3.39，CI：1.98-5.82，P＜0.0001）均与MGUS进展风险增加相关，在多变量模型中这些因素保持独立相关性（c统计量=0.75，CI：0.68-0.82）。BMI与进展的关联性在女性（HR=3.55，CI：1.06-11.9，P=0.04）中强于男性（HR=1.39，CI：0.57-3.36，P=0.47），尽管BMI与性别间的交互作用未达显著水平（P=0.15）。总之，高BMI是MGUS进展的预后因素，独立于免疫球蛋白类型、M蛋白水平和FLCr。这种关联在女性中可能更为显著。
肿瘤(癌症)患者之家