[Effect of vitamin D deficiency on cardiac autonomic nerve function in obese pre-school children]

OBJECTIVE

To study the effect of vitamin D (VitD) deficiency on cardiac autonomic nerve function in obese pre-school children.

METHODS

A total of 242 pre-school children with simple obesity were enrolled, and according to the serum 25-(OH) VitD level, they were divided into VitD deficiency group (76 children), VitD insufficiency group (83 children), and VitD sufficiency group (83 children). The three groups were compared in terms of deceleration capacity (DC) of heart rate, acceleration capacity (AC) of heart rate, and heart rate variability (HRV). The correlations of VitD level with DC, AC, and HRV were analyzed for the VitD insufficiency and VitD deficiency groups.

RESULTS

The VitD deficiency group had the lowest DC, root mean square of successive differences between adjacent RR intervals (RMSSD), and low-frequency power (LF) and the highest AC (P<0.05). The VitD insufficiency group had significantly lower DC, RMSSD, and LF and significantly higher AC compared with the VitD sufficiency group (P<0.05). The VitD deficiency group had significantly lower standard deviation of normal-to-normal RR intervals (SDNN) and high-frequency power (HF) than the VitD sufficiency group (P<0.05). In the VitD deficiency group, VitD level was positively correlated with DC, SDNN, standard deviation of average normal-to-normal RR intervals, RMSSD , LF, and HF and was negatively correlated with AC (P<0.05). In the VitD insufficiency group, VitD level was negatively correlated with AC (P<0.05).

CONCLUSIONS

Obese pre-school children with VitD insufficiency or deficiency have cardiac autonomic dysfunction, and cardiac vagal tone decreases with the reduction in VitD level.

[Effect of vitamin D deficiency on cardiac autonomic nerve function in obese pre-school children]

OBJECTIVE

To study the effect of vitamin D (VitD) deficiency on cardiac autonomic nerve function in obese pre-school children.

METHODS

A total of 242 pre-school children with simple obesity were enrolled, and according to the serum 25-(OH) VitD level, they were divided into VitD deficiency group (76 children), VitD insufficiency group (83 children), and VitD sufficiency group (83 children). The three groups were compared in terms of deceleration capacity (DC) of heart rate, acceleration capacity (AC) of heart rate, and heart rate variability (HRV). The correlations of VitD level with DC, AC, and HRV were analyzed for the VitD insufficiency and VitD deficiency groups.

RESULTS

The VitD deficiency group had the lowest DC, root mean square of successive differences between adjacent RR intervals (RMSSD), and low-frequency power (LF) and the highest AC (P<0.05). The VitD insufficiency group had significantly lower DC, RMSSD, and LF and significantly higher AC compared with the VitD sufficiency group (P<0.05). The VitD deficiency group had significantly lower standard deviation of normal-to-normal RR intervals (SDNN) and high-frequency power (HF) than the VitD sufficiency group (P<0.05). In the VitD deficiency group, VitD level was positively correlated with DC, SDNN, standard deviation of average normal-to-normal RR intervals, RMSSD , LF, and HF and was negatively correlated with AC (P<0.05). In the VitD insufficiency group, VitD level was negatively correlated with AC (P<0.05).

CONCLUSIONS

Obese pre-school children with VitD insufficiency or deficiency have cardiac autonomic dysfunction, and cardiac vagal tone decreases with the reduction in VitD level.

[Cardiac autonomic nerve function in obese school-age children]

OBJECTIVE

To analyze the deceleration capacity (DC) of heart rate, acceleration capacity (AC) of heart rate, and heat rate variability (HRV) in obese school-age children, and to observe the correlations of BMI with DC, AC, and HRV in these children.

METHODS

A total of 108 obese school-age children were selected, including 75 cases of ortholiposis and 33 cases of dyslipidemia. A total of 103 healthy school-age children were selected as control group. All the subjects underwent 24-hour ambulatory electrocardiography. The comparisons of DC, AC, and HRV were made between the obese and control groups, as well as between children with ortholiposis and dyslipidemia in the obese group. The correlations of BMI with DC, AC, and HRV were analyzed in the obese group.

RESULTS

The obese group showed lower DC, standard deviation of normal-to-normal R-R intervals (SDNN), standard deviation of the average normal-to-normal intervals (SDANN), root mean square of successive differences (RMSSD), low-frequency power (LF), and high-frequency power (HF) than the control group. The AC of the obese group was significantly higher than that of the control group (P<0.05). In the obese group, children with dyslipidemia had significantly lower DC, SDNN, SDANN, RMSSD, LF, and HF, but significantly higher AC and BMI, as compared with those with ortholiposis (P<0.01). In the obese group, BMI was negatively correlated with DC, SDNN, SDANN, RMSSD, and HF (P<0.05), but positively correlated with AC (P<0.05).

CONCLUSIONS

Obese school-age children have impaired autonomic nerve function, presenting with reduced vagal tone, which is particularly prominent in those with dyslipidemia. The more obese the children, the lower the vagal tone, which may increase the risks of cardiovascular diseases.

[Cardiac autonomic nerve function in obese school-age children]

OBJECTIVE

To analyze the deceleration capacity (DC) of heart rate, acceleration capacity (AC) of heart rate, and heat rate variability (HRV) in obese school-age children, and to observe the correlations of BMI with DC, AC, and HRV in these children.

METHODS

A total of 108 obese school-age children were selected, including 75 cases of ortholiposis and 33 cases of dyslipidemia. A total of 103 healthy school-age children were selected as control group. All the subjects underwent 24-hour ambulatory electrocardiography. The comparisons of DC, AC, and HRV were made between the obese and control groups, as well as between children with ortholiposis and dyslipidemia in the obese group. The correlations of BMI with DC, AC, and HRV were analyzed in the obese group.

RESULTS

The obese group showed lower DC, standard deviation of normal-to-normal R-R intervals (SDNN), standard deviation of the average normal-to-normal intervals (SDANN), root mean square of successive differences (RMSSD), low-frequency power (LF), and high-frequency power (HF) than the control group. The AC of the obese group was significantly higher than that of the control group (P<0.05). In the obese group, children with dyslipidemia had significantly lower DC, SDNN, SDANN, RMSSD, LF, and HF, but significantly higher AC and BMI, as compared with those with ortholiposis (P<0.01). In the obese group, BMI was negatively correlated with DC, SDNN, SDANN, RMSSD, and HF (P<0.05), but positively correlated with AC (P<0.05).

CONCLUSIONS

Obese school-age children have impaired autonomic nerve function, presenting with reduced vagal tone, which is particularly prominent in those with dyslipidemia. The more obese the children, the lower the vagal tone, which may increase the risks of cardiovascular diseases.