Fibroblast growth factor–21 (FGF21), a protein that regulates carbohydrate and lipid metabolism, could be a biomarker in patients with bipolar mania, a new study suggests.
“In addition, our data indicates that FGF21 may monitor and/or prevent metabolic abnormalities induced by psychotropic drugs,” wrote Qing Hu of Xiamen City Xianyue Hospital, in Fujian, China, and associates. The study was published in Psychiatry Research.
To investigate how the expression of FGF21 changes in response to psychotropics taken by patients with bipolar mania, the researchers recruited 99 inpatients with bipolar mania with or without psychosis and 99 healthy controls. Eighty-two of the patients received psychotropics only, and 17 received psychotropics and lipid-lowering or hypotensive agents. Those in the smaller group were later excluded from follow-up.
At baseline, no significant differences were found between the patients and controls on several metabolic measures, such as cholesterol and apolipoprotein. The patients with bipolar mania had higher uric acid and triglyceride levels, although the latter was not statistically significant. However, compared with the FGF21 serum levels of the controls.
After 4 weeks of taking the antipsychotics, the patients experienced increases in several metabolic measures, such as BMI (23.68 kg/m2 vs. 24.02 kg/m2), LDL cholesterol (2.61 mg/dL vs. 2.98 mg/dL), and glucose (4.74 mg/dL vs. 4.88 mg/dL). However, their FGF21 levels declined, from 279.45 pg/mL to 215.12 pg/mL.
“In light of these findings, our future research will focus on investigating whether ... the change in FGF21 expression is a causal factor or a consequence of bipolar disorder,” the investigators wrote.
They cited several limitations. One is that psychotropic dosages were not discussed, and another is that evaluation data from the Young Mania Rating Scale were missing.
The researchers reported no conflicts of interest.
SOURCE: Hu Q et al. Psychiatry Res. 2019;272:643-8.