MON-099 Age-Related Differences in Appetite Regulation among Adults with Obesity: More Than Just Hunger and PYY and Ghrelin? Oh My!

Background: There is evidence that the regulation of energy intake (EI) changes with aging. The “anorexia of aging” is defined as the reduction of hunger and EI in late life. Yet, despite decreased EI and weight loss, obesity has also increased among the geriatric population. With few studies in older adults with obesity, we aimed to address this paradox by evaluating age-related differences in appetite regulation. Hypotheses: We hypothesized that there is decreased ad libitum EI in older adults with obesity (O(Ob)) as compared to younger adults with obesity (Y(Ob)), related to decreased subjective appetite and eating-related behaviors, and differences in appetite-related peptides. Methods: We performed a cross-sectional pilot study in O(Ob) aged 65-85 years as compared to Y(Ob) aged 21-45 years, all with BMI 30-40 kg/m(2). Appetite-related ratings and peptides, eating-related behaviors and ad libitum EI in O(Ob) were compared to Y(Ob). Exclusions included comorbidities and medications that affect appetite and weight, tobacco or marijuana use, body weight >300 lbs, or weight loss in the past 6 months. Appetite (Visual Analogue Scales for hunger and satiety) and hormones (ghrelin, peptide YY [PYY] and glucagon-like peptide-1 [GLP-1]) were measured in the fasted state and every 30 minutes for 3 hours following a test breakfast meal. Eating behaviors and ad libitum EI at a lunch meal were also measured. Results: Data from 6 O(Ob) and 15 Y(Ob) were analyzed (age 71±3 vs. 35±8 yrs, p<0.001, respectively). BMI was similar (O(Ob) 32.8±1.2 vs. Y(Ob) 32.6±0.5 kg/m(2), p=0.85) as was % body fat (O(Ob) 39.8±2.4 vs. Y(Ob) 41.4±1.5 %, p=0.58). Ad libitum EI was similar though it trended to be higher in O(Ob) (O(Ob) 784±66 vs. Y(Ob) 645±48 kcals, p=0.10). Hunger area under the curve (AUC) was lower in O(Ob) (O(Ob) 3,702±1,004 vs. Y(Ob) 5,654±432 mm, p=0.04). PYY AUC was higher (O(Ob) 26,419±2,501 vs. Y(Ob) 20,894±1,277 pg/mL, p=0.04) and ghrelin AUC trended to be lower in O(Ob) (O(Ob) 109,772±6,689 vs. Y(Ob) 132,360±8,616 pg/mL, p=0.08). Differences in satiety AUC (O(Ob) 9,174±1,150 vs. Y(Ob) 8,580±363 mm, p=0.52), food cravings (O(Ob) 32.2±3.7 vs. Y(Ob) 39.7±2.8, p=0.11), restraint (O(Ob) 11.0±1.3 vs. Y(Ob) 9.5±1.0, p=0.37), disinhibition (O(Ob) 5.6±1.3 vs. Y(Ob) 6.9±1.0, p=0.30), leptin (O(Ob) 46.4±18.6 vs. Y(Ob) 64.0±8.9 ng/mL, p=0.34) and GLP-1 (O(Ob) 2,995±874 vs. Y(Ob) 994±381 pmol/L, p=0.11) were not statistically significant. Conclusions: Despite a trend toward higher ad libitum EI, O(Ob) had lower hunger, higher PYY and possibly lower ghrelin than Y(Ob). There appear to be age-related mechanistic differences in appetite regulation between older and younger adults with obesity that deserve further investigation, with implications for more tailored obesity treatments. Research Support: NIH Grant T32, ADA Translational Science Award, VA Eastern Colorado Health Care System GRECC Pilot Project and Fellowship