Severe obesity in young adults : characterization and treatment outcomes with emphasis on mental health aspects

Abstract

Background: Obesity (body mass index [BMI] ≥30 kg/m2) is associated with a range of physical and psychiatric comorbidities and premature mortality. Young adulthood (here 16-25 years) constitutes a vulnerable period for weight gain, poor weight loss results, and mental health problems. Up to 8.3% of Swedish young adults are classified as obese. In spite of the fact that the peak incidence for obesity occurs during young adulthood, this age period has been generally overlooked in clinical obesity research, particularly in regard to obesity-related mental health problems.

Aim: To characterize severe obesity (BMI ≥35 kg/m2) in young adulthood (16-25 years) with emphasis on mental health aspects, and to study long-term outcomes (weight loss, adverse events, loss-to-follow-up and health-related quality of life [HRQL]) in young (18-25 years) vs older (≥26 years) adults after Roux-en-Y gastric bypass (RYGB).

Methods: In Study I, we used cross-sectional self-reported questionnaire data on obesity-related comorbidities, mental health, self-esteem, lifestyle and health-related quality of life; physical fitness tests; biochemical data on micronutritional deficiencies; and anthropometry from n=165 young adults, aged 16-25 years who were about to start treatment at the Karolinska University Hospital Obesity Center. In Study II, we compared cross-sectional questionnaire patient data (n=121 treatment-seekers to the Obesity Center, 18-25 years) on mental distress, self-reported suicide attempts, physical/psychosomatic symptoms, and quality of life with data on n=363 normal-weight responders to the Stockholm Public Health Cohort 2010 who were individually matched 3:1 for age, gender and socioeconomic status. For Studies III-IV, we frequency matched n=3,531 young (18-25 years) to n=17,137 older (26-74 years) patients in the Scandinavian Obesity Surgery Registry for BMI, gender and year of surgery to compare weight loss, adverse events, loss-to-follow-up and changes in HRQL between matching groups.

Results: In Study I, we found consistent indications of poor mental and obesity-related health problems (up to 55%), high levels of cardiometabolic risk factors (up to 82%) and micronutritional deficiencies (48%) in treatment-seeking young adults (mean BMI 39.2 kg/m2 [SD: 5.2], 80% women). In Study II, we found an increased risk of mental distress (adjusted relative risk [RR]=1.76, 95% CI: 1.38-2.24), suicide attempts (adjusted RR=2.04, 95% CI: 1.06-3.95), physical/psychosomatic symptoms (adjusted RR=1.59-2.95) and poor quality of life (range of adjusted RR=1.97-6.61) in obese treatment-seekers (mean BMI 39.8 kg/m2 [SD: 5.3], 81% women) compared to population controls (mean BMI 22.4 kg/m2 [SD: 4.0], 81% women). In Study III, a total of n=369 young (37.0% of eligible) and n=2,210 older (46.1%) adults were followed-up 5 years after RYGB. Young adults displayed higher weight loss (31.8% vs 28.2%) at 5 years, more long-term adverse events (any kind of adverse events between 2-5 years: 20.3% vs 12.7%, adjusted OR=1.72, 95% CI: 1.29-2.31; serious adverse events between 2-5 years [Clavien-Dindo ≥3b]: 14.1% vs 6.9%, adjusted OR=2.06, 95% CI: 1.45-2.92) and higher loss-to-follow-up throughout the study period (range of adjusted RR=1.16-2.13), all, p <0.001. In Study IV, n=138 young (20.7% of those eligible) and n=1,021 older (31.8%) adults were available for follow-up 5 years post-RYGB. Both young and older adults displayed clinically relevant improvements in physical HRQL 5 years after RYGB compared to baseline values, while no change or deterioration in mental HRQL was observed in both groups. Older adults generally experienced greater HRQL improvements than the young adults in adjusted analyses.

Conclusion: Treatment-seeking young adults with severe obesity constitute a vulnerable patient group with a wide array of obesity-related comorbidities, particularly mental health issues. While we found promising weight loss results and improvements in physical HRQL in young adults 5 years after RYGB, there were also higher numbers of long-term adverse events, drop-outs and generally poor improvements in HRQL in young vs older adults. Future research needs to address the impact of mental distress on the development and treatment of obesity in young adults. Studies on the significance of and the etiology behind our data showing more serious adverse events and higher loss-to-follow-up in the younger RYGB-patients are needed.