Although dapagliflozin plus exenatide compared with placebo had no effect on LH/HF ratio after 10 days and 16 weeks, dapagliflozin plus exenatide reduced RMSSD (10 days: − 11.4 ± 4.6 p = 0.015; 16 weeks: − 10.7 ± 4.8 p = 0.029) and SDNN (10 days: − 9.6 ± 3.7 p = 0.012; 16 weeks: − 8.7 ± 3.9 p = 0.030) (an indicator of reduced parasympathetic activity) (Table 3; Fig. 2). The gene discussed is PLOD1; the disease is hydrops fetalis.