Methylphenidate for ADHD Treatment May Be Associated With Low BMI

Methylphenidate (MPH) use in boys with attention-deficit/hyperactivity disorder (ADHD) appears to be associated with low body mass index (BMI), according to data published in BMC Psychiatry. However, this effect appeared to change based on age bracket and/or duration of MPH use. No evidence was found to confirm the association of MPH with short stature or changes in blood pressure. 

Investigators used data from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) database. KiGGS collected demographic and clinical information by random sampling from children age ≤17 living in 167 representative German municipalities between 2003 and 2006 (n=17,461). Researchers extracted data on BMI, systolic blood pressure (SBP), diastolic blood pressure (DBP), and MPH use in boys with ADHD. A control group of boys without ADHD was also selected.

A total of 4244 boys were included in the study who were categorized into by the following groups: MPH use <12 months (n=65), MPH use ≥12 months (n=53), ADHD controls with no MPH use (n=320), and non-ADHD controls (n=3806). Age demographics were nearly evenly divided between 6 to 10 (51.7%) and 11 to 15 (48.3%). Data were analyzed separately for each age group. In boys age 6 to 10,, boys with MPH use <12 months were significantly more likely to have a BMI ≤third percentile compared with the non-ADHD control group (odds ratio [OR], 4.52; 95% CI, 1.54-13.28; P =.006). However, in boys age 11 to 15, boys with MPH use ≥12 months were more likely to have a BMI ≤third percentile compared with non-ADHD controls (OR, 3.59; 95% CI, 1.06-12.22; P =.040). This effect was not observed in either age bracket in boys with MPH use and ADHD controls. In addition, no significant differences in mean height were observed in any of the 4 study groups. Mean SBP and DBP values were similar across groups, although stage 1 hypertension based on SBP and/or DBP was observed most frequently in boys taking MPH ≥12 months. However, this effect was not statistically significant. Of note, the percentage of ADHD controls with raised SBP was significantly lower than in the non-ADHD group (P =.016), suggesting that ADHD does not raise the risk for elevated SBP.

Analyses of the KiGGS dataset indicate an association between MPH use in boys with ADHD and low BMI, although the effect was stronger in boys age 6 to 10 and with MPH use <12 months. There were no significant differences observed between the non-ADHD control group and boys age 6 to 10 with MPH use ≥12 months or boys age 11 to 15 with MPH use <12 months.

Researchers concluded that the relationship between ADHD, MPH use, and growth appears complex, given that a consistent effect could not be observed across all ADHD conditions. Analyses of cardiovascular outcomes following MPH use were also inconclusive, emphasizing the need for further research. Clinicians may find these cross-sectional results useful in titrating MPH treatment in pre- and post-pubertal boys with ADHD.

Reference

McCarthy S, Neubert A, Man KKC, et al. Effects of long-term methylphenidate use on growth and blood pressure: results of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS). BMC Psychiatry. 2018;18:327.