Effects of pre- and post-diagnosis of malignant neoplasms total cholesterol difference on all-cause death in the Kailuan study population / 肿瘤研究与临床

ABSTRACT

Objective:To explore the effects of pre- and post-diagnosis of malignant neoplasms total cholesterol difference on all-cause death in the Kailuan study population.Methods:A prospective cohort study method was used to observe on the job and retired workers who were diagnosed with malignant neoplasms during the healthy physical examination and had the complete data of total cholesterol pre- and post-diagnosis of malignant neoplasms at Kailuan (Group) Limited Liability Corporation from June 2006 to December 2015. Medical insurance system and medical records case management system of Kailuan General Hospital were used to retrieve the confirmed diagnosis time of participants with malignant neoplasms. SAS 9.4 software was used to extract the physical examination data of participants diagnosed as malignant neoplasms before and after 2 years. The whole participants were divided into 4 groups according to the quartile of the total cholesterol difference pre- and post-diagnosis of cancer. The first quartile group the total cholesterol difference <-0.93 mmol/L (823 cases), the second quartile group the total cholesterol difference≥-0.93 mmol/L and <-0.21 mmol/L (811 cases), the third quartile group the total cholesterol difference≥-0.21 mmol/L and <0.49 mmol/L (832 cases), the forth quartile group the total cholesterol difference≥0.49 mmol/L (833 cases). The incidence density was used to calculate the mortality of different total cholesterol difference quartile groups, and the Cox proportional hazards model was used to analyze the influencing factors of all-cause death of all quartile groups.Results:Totally, 1 564 cases had all-cause death during median 2.46 years of follow-up time. There were 481, 440, 333, 310 death cases respectively of 4 quartile groups. The death rates of all quartile groups were 230.10/1 000 person-years, 163.90/1 000 person-years, 115.34/1 000 person-years, and 83.44/1 000 person-years respectively ( χ2 = 604.62, P < 0.001). After adjusting for confounding factors, the Cox proportional hazards model analysis showed that compared with the first quartile group, the hazard ratio with the 95% confidence interval of all-cause death in the second, third, and fourth quartile groups was 0.86 (0.76-0.98), 0.62(0.54-0.72) and 0.58 (0.50-0.67) respectively (all Ptrend < 0.001). After adjusting for confounding factors of patients with cancer in different location, the forth quartile group except for cancer in thyroid, breast, prostate, testis and urinary system, all Ptrend was less than 0.05 compared with that of the first quartile group. Conclusion:Among Kailuan study population, the smaller decline or even rise in total cholesterol level of post-diagnosis compared with that of pre-diagnosis is a protective factor of all-cause death.