Increased prevalence of obesity in narcoleptic patients and relatives

Increased Body Mass Indices (BMIs), increased prevalences of non insulin-de pendent diabetes and sleep apnoe syndrome have been reported to be associat ed with narcolepsy. Our objective was to explore and possibly confirm the a ssociation of narcolepsy and increased BMI. In addition, we addressed the q uestion whether increased BMIs also occur in relatives of narcoleptic patie nts. Together with narcolepsy-related clinical parameters we measured body weight and height of 132 narcoleptic patients who agreed to participate in our narcolepsy research program. In addition, 52 first degree relatives of 22 index patients, mostly from multiplex families, were included in the stu dy. Data were compared to published general population surveys, recently co nducted in Germany and Switzerland as well as to collective of 104 psychiat ric inpatients. Narcoleptic patients had significantly increased BMIs in co mparison to general populations or psychiatric controls. BMIs of first degr ee relatives were lower than those of index patients but significantly high er than those found in the general population. BMIs were not related to sym ptom severity or to medication status. Thus, the elevated BMIs appeared not to be secondary to behavioral consequences of narcolepsy but may reflect a trait at least partially common to index patients and relatives.