Somatic comorbidity in anorexia nervosa: First results of a 21-year follow-up study on female inpatients

BACKGROUND Anorexia nervosa is a severe psychosomatic disease with somatic complications in the long-term course and a high mortality rate. Somatic comorbidities independent of anorexia nervosa have rarely been studied, but pose a challenge to clinical practitioners. We investigated somatic comorbidities in an inpatient cohort and compared somatically ill anorexic patients and patients without a somatic comorbidity. In order to evaluate the impact of somatic comorbidity for the long-term course of anorexia nervosa, we monitored survival in a long-term follow-up. METHOD One hundred and sixty-nine female inpatients with anorexia nervosa were treated at the Charité University Medical Centre, Campus Benjamin Franklin, Berlin, between 1979 and 2011. We conducted retrospective analyses using patient's medical and psychological records. Information on survival and mortality were required through the local registration office and was available for one hundred patients. The mean follow-up interval for this subgroup was m = 20.9 years (sd = 4.7, min = 13.3, max = 31.6, range = 18.3). We conducted survival analysis using cox regression and included somatic comorbidity in a multivariate model. RESULTS N = 41 patients (24.3%) showed a somatic comorbidity, n = 13 patients (7.7%) showed somatic comorbidities related to anorexia nervosa and n = 26 patients (15.4%) showed somatic comorbidities independent of anorexia nervosa, n = 2 patients showed somatic complications related to other psychiatric disorders. Patients with a somatic comorbidity were significantly older (m = 29.5, sd = 10.3 vs m = 25.0, sd = 8.7; p = .006), showed a later anorexia nervosa onset (m = 24.8, sd = 9.9 vs. m = 18.6, sd = 5.1; p < .000) and a longer duration of treatment in our clinic (m = 66.6, sd = 50.3 vs. m = 50.0, sd = 47; p = .05) than inpatients without somatic comorbidity. Out of 100 patients, 9 patients (9%) had died, on average at age of m = 37 years (sd = 9.5). Mortality was more common among inpatients with somatic comorbidity (n = 6, 66.7%) than among inpatients without a somatic disease (n = 3, 33.3%; p = .03). Somatic comorbidity was a significant coefficient in a multivariate survival model (B = 2.32, p = .04). CONCLUSION Somatic comorbidity seems to be an important factor for anorexia nervosa outcome and should be included in multivariate analyses on the long-term course of anorexia nervosa as an independent variable. Further investigations are needed in order to understand in which way anorexia nervosa and a somatic disease can interact.