Zemel, Babette S.

AbstractObjectivesChildren with inflammatory bowel disease (IBD) often have low body mass index (BMI). BMI does not distinguish between fat and lean mass. Body composition deficits may be associated with worse clinical outcomes. We examined the prevalence of risk factors associated with body composition deficits in youth with pediatric‐onset IBD, and factors associated with low lean mass in the presence of a normal BMI Z‐score (BMI‐Z).MethodsNewly diagnosed IBD patients ages 5–20 years with whole body dual energy x‐ray absorptiometry scans acquired between 2014 and 2019 were included. Appendicular lean soft tissue mass index (AppLSTMI) and fat mass index (FMI) were expressed as age and sex‐specific Z‐scores. Clinical and demographic data were collected retrospectively. Logistic regression was used to assess associations with body composition outcomes.ResultsFive hundred sixteen patients were included, 26% had AppLSTMI Z‐score (AppLSTMI‐Z) < −2, 4% had BMI‐Z < −2, and none had FMI Z‐score (FMI‐Z) < −2. Increased risk of low AppLSTMI‐Z associated with Crohn's diagnosis, Asian ethnicity, disease activity, elevated platelets, and glucocorticoid use. Females had lower FMI‐Z. Low AppLSTMI‐Z within the context of BMI‐Z (n = 112) was associated with Crohn's disease, Asian (odds ratio [OR] = 3.77, p = 0.001) and Black identity (OR = 0.32, p = 0.02), and elevated platelets (OR = 1.76, p = 0.02) compared to those with normal BMI‐Z and normal AppLSTMI‐Z.ConclusionsBMI is a poor indicator of body composition in children with IBD as it masks lean mass deficits which are highly prevalent. Future studies regarding the long‐term consequences and reversibility of this deficit are warranted.

OBJECTIVELatent autoimmune diabetes in adults (LADA) shares clinical features with both type 1 and type 2 diabetes; however, there is ongoing debate regarding the precise definition of LADA. Understanding its genetic basis is one potential strategy to gain insight into appropriate classification of this diabetes subtype.RESEARCH DESIGN AND METHODSWe performed the first genome-wide association study of LADA in case subjects of European ancestry versus population control subjects (n = 2,634 vs. 5,947) and compared against both case subjects with type 1 diabetes (n = 2,454 vs. 968) and type 2 diabetes (n = 2,779 vs. 10,396).RESULTSThe leading genetic signals were principally shared with type 1 diabetes, although we observed positive genetic correlations genome-wide with both type 1 and type 2 diabetes. Additionally, we observed a novel independent signal at the known type 1 diabetes locus harboring PFKFB3, encoding a regulator of glycolysis and insulin signaling in type 2 diabetes and inflammation and autophagy in autoimmune disease, as well as an attenuation of key type 1–associated HLA haplotype frequencies in LADA, suggesting that these are factors that distinguish childhood-onset type 1 diabetes from adult autoimmune diabetes.CONCLUSIONSOur results support the need for further investigations of the genetic factors that distinguish forms of autoimmune diabetes as well as more precise classification strategies.

114 Background: We evaluated baseline differences in arm tissue composition (fat mass, lean mass, bone mineral content [BMC] and bone mineral density [BMD]) between the affected and unaffected arms in women with breast cancer-related lymphedema (BRCL). We compared changes in arm tissue composition and self-reported lymphedema symptoms after one-year of weight-lifting vs. usual-care. Methods: We utilized data from the PAL trial that included 141 women with BRCL. Arm tissue composition was quantified using dual-energy x-ray absorptiometry. The severity of lymphedema was quantified using self-report survey. Weight-lifting was performed at community fitness facilities. Results: At baseline, the affected arm had more fat (D= 89.7±21.0g; P < 0.001) and lean mass (D= 149.1±25.3g; P < 0.001), but less BMC (D= -3.2±0.9g; P < 0.001) than the unaffected arm. No difference was observed in BMD. After 12-months of weight-lifting, composition of the affected arm was improved: lean mass (71.2±27.9g; P = 0.01) and BMD (0.01±0.01g; P = 0.02) increased, arm fat percentage decreased (0.01±0.01; P = 0.003). No changes observed in fat mass and BMC. Baseline body mass index and BCRL grade modified the relationship between weight-lifting and tissue composition changes. Increases in lean mass were associated with less severe BCRL symptoms. With every one-percent decrease in arm fat percentage, affected limb volume reduced 13.81mL. Conclusions: Among women with BRCL, affected and unaffected arms differ in tissue composition. These differences may be improved with weight-lifting. Changes in arm tissue composition correlate with improved BCRL symptoms. Investigating the combined effects of exercise and weight-loss on arm tissue composition and BCRL symptoms may provide additional insight to the benefits of lifestyle modification on lymphedema biology. Clinical trial information: NCT00194363.