Value of abnormal circadian rhythm of heart rate predicting the all-cause mortality in stage 5 chronic kidney disease patients / 中华肾脏病杂志

Objective:To investigate the predictive value of abnormal heart rate circadian rhythm for all-cause mortality in stage 5 chronic kidney disease (CKD 5) patients.Methods:The retrospective study was performed in CKD 5 patients enrolled from the First Affiliated Hospital of Nanjing Medical University (Jiangsu Province Hospital) and the Affiliated BenQ Hospital of Nanjing Medical University from February, 2011 to December, 2019. A total of 159 healthy volunteers were enrolled as the healthy control group during the same period. The circadian rhythm of heart rate was monitored by 24-hour Holter. Related indices (including 24-hour, daytime and nighttime mean heart rate, night/day heart rate ratio, 24-hour maximum heart rate, 24-hour minimum heart rate and difference between maximum and minimum of 24-hour heart rate) were calculated. Non-dipping heart rate was defined as night/day heart rate ratio greater than 0.9. Cox regression model was used to analyze the risk factors of all-cause mortality in CKD 5 patients. Kaplan-Meier survival curve and Log-rank test were used to compare the differences of cumulative mortality between high ratio group (night/day heart rate ratio>0.91) and low ratio group (night/day heart rate ratio≤0.91). The nonlinear relationship between night/day heart rate ratio and all-cause mortality was analyzed by restricted cubic spline plot. Time-dependent receiver operating characteristic (ROC) curve was used to analyze the predictive value of night/day heart rate ratio for all-cause mortality in CKD 5 patients.Results:A total of 159 healthy volunteers and 221 CKD 5 patients were included in this study. There were 123 males (55.66%) and the age was (52.72±13.13) years old in CKD 5 patients. The total median follow-up time was 50.0 months. Compared with controls, 24-hour, nighttime mean heart rate, 24-hour minimum heart rate in CKD 5 patients were increased (all P<0.05), furthermore, the night/day heart rate ratio was higher [(0.91±0.09) vs (0.81±0.08), P<0.001], showing "non-dipping heart rate". However, the 24-hour maximum heart rate and the difference between maximum and minimum of 24-hour heart rate in CKD 5 patients were lower than controls (both P<0.05). Multivariate Cox regression analysis showed that the increased night/day heart rate ratio (per 0.1 increase, HR=1.557, 95% CI 1.073-2.258, P=0.020) was an independent influencing factor for all-cause mortality in CKD 5 patients. Kaplan-Meier survival curve analysis showed that the cumulative mortality of the high ratio group was significantly increased than that of the low ratio group (Log-rank test χ 2=7.232, P=0.007). From the restricted cubic spline plot, there was a linear effect between night/day heart rate ratio and all-cause mortality ( P=0.141), and when night/day heart rate ratio was above 0.91, the risk of all-cause mortality was significantly increased in CKD 5 patients. According to time-dependent ROC curve, the accuracy of night/day heart rate ratio in predicting all-cause mortality was 70.90% even when the survival time was up to 70.0 months. Conclusions:The circadian rhythm of heart rate in CKD 5 patients displays "non-dipping" state. High night/day heart rate ratio is an independent influencing factor for all-cause mortality in CKD 5 patients.

Effects of parathyroidectomy on heart rate circadian rhythm in patients with stage 5 chronic kidney disease combined with severe secondary hyperparathyroidism / 中华肾脏病杂志

Objective:To observe heart rate circadian rhythm in patients with chronic kidney disease (CKD) stage 5 and to analyze the effects of parathyroidectomy (PTX) on heart rate circadian rhythm in severe secondary hyperparathyroidism (SHPT) patients.Methods:A cross-sectional observation was performed in 213 patients with CKD stage 5 and 96 controls, and the patients were divided into those with severe SHPT (PTX group, n=70) and without severe SHPT (non-PTX group, n=143). Forty-six PTX patients were followed up prospectively. The baseline data were compared among these groups. Holter electrocardiogram was performed for each participant. Non-dipping heart rate was defined as night/day heart rate ratio greater than 0.9. Multiple linear regression analysis was used to analyze the related factors of heart rate circadian rhythm in patients with CKD stage 5. Results:The 24-hour, daytime and nighttime mean heart rate in patients with CKD stage 5 were all higher than those in controls, especially in PTX group (all P<0.05). The night/day heart rate ratios of controls and CKD stage 5 patients were (0.81±0.08) and (0.91±0.08) respectively ( P<0.01). Correlation analysis showed 24-hour and daytime or nighttime mean heart rate in patients with CKD stage 5 were positively correlated with serum levels of phosphorus and ln(alkaline phosphatase), while nighttime mean heart rate and night/day heart rate ratio were positively related with serum intact parathyroid hormone level. After adjusting with postoperative follow-up period (median time: 10.9 months), 24-hour and nighttime mean heart rate, and night/day heart rate ratio in PTX patients all decreased significantly (all P<0.01). Conclusions:Heart rate is increased and circadian rhythm is abnormal in patients with CKD stage 5, which are related with mineral and bone disorder. PTX significantly decreases 24-hour and nighttime mean heart rate in severe SHPT patients, and improves the heart rate circadian rhythm.

Effect of underground work on cardiovascular system in coal miners / 中南大学学报(医学版)

OBJECTIVE@#To study the effect of underground work on cardiovascular system health in coal miners.
@*METHODS@#Male coal miners, who received electrocardiographic examinations between June, 2013 and August, 2014 in Hunan Prevention and Treatment Institute for Occupational Diseases to exclude pneumoconiosis, were enrolled for this study (n=3 134). Miners with 2 years or more underground work experience were selected as the exposed group (n=2 370), while miners without underground work experience were selected as the control group (n=764). The prevalence of electrocardiographic abnormalities and the influential factors were compared between the 2 groups.
@*RESULTS@#The prevalences of electrocardiographic abnormalities, hypertension, heart rate abnormalities and cardiovascular system abnormalities in the exposed group vs the control group were 37.6% vs 25.4%, 20.5% vs 13.4%, 5.7% vs 6.0%, 49.8% vs 35.2%, respectively. The cardiovascular system abnormalities were correlated with the underground work (OR=3.128, 95% CI: 1.969-4.970), the underground work experience (OR=1.205, 95% CI: 1.070-1.358) and the type of works (mining worker OR=1.820, 95% CI: 1.527-2.169; auxiliary worker OR=1.937, 95% CI: 1.511-2.482; other worker OR=3.291, 95%CI: 2.120-5.109).
@*CONCLUSION@#Underground work may increase the prevalence of cardiovascular system abnormalities for coal miners. The longer the coal miners work in underground, the higher the risk of the cardiovascular system abnormalities they are.

Analysis of pulmonary dysfunction of 1 953 coal miners in Hunan Province / 中南大学学报(医学版)

OBJECTIVE@#To explore the effect of dust exposure, type of work, age, length of service and duration of dust exposure on pulmonary function in coal miners by pulmonary function tests.
@*METHODS@#A total of 1 953 coal miners, who received occupational healthy examination and pulmonary function tests during June, 2013 and August, 2014 in Hunan Prevention and Treatment Institute, were enrolled for this study.
@*RESULTS@#A total of 1 302 miners (66.7%) displayed pulmonary dysfunction, including 1 139 with mild dysfunction (58.3%) and 163 with moderate or more serious dysfunction (8.3%). The risk factors for pulmonary dysfunction were age (OR=1.329, 95% CI: 1.196-1.620), dust exposure duration (OR=1.267, 95% CI: 1.136-1.413) and type of works (mining workers OR=1.156, 95% CI: 1.033-1.293; all P<0.05).
@*CONCLUSION@#The incidence rate of pulmonary dysfunction in coal miners is relatively high in Hunan Province. Most of them are mild dysfunction. The incidence rate of pulmonary dysfunction in mining works is statistically higher than that in other work types. Older workers and long duration-exposed workers are more likely to have pulmonary dysfunction.