BACKGROUND

Secondary hypertension has emerged as a major public health problem in China. Early diagnosis and treatment can significantly improve the clinical outcomes. However, data on the current cause composition in China are seldom reported.

OBJECTIVE

To describe the trends in cause-related comorbidities in hospitalized patients with secondary hypertension in China from 2013 to 2016.

METHODS

This was a retrospective analysis based on the national Hospital Quality Monitoring System (HQMS) database, which collects information from the front pages of in-hospital medical records. Hospitalized patients with secondary hypertension from 746 tertiary hospitals that consistently uploaded data to the HQMS from 2013 to 2016 were enrolled. All diagnoses were identified using International Classification of Diseases version 10 (ICD-10) diagnostic codes. Descriptive analyses were used to determine the proportions of secondary hypertension causes and changing trends over 4 years.

RESULT

The study collected data on 402 371 hospitalized patients with secondary hypertension from the HQMS during 2013-2016. Secondary hypertension caused by renal parenchymal disease ranked first and accounted for more than 50%. Obstructive sleep apnea syndrome (OSAS) followed closely with a rate of approximately 25%. Primary aldosteronism presented the highest proportion among all causes of endocrine hypertension. Regarding longitudinal changes over time, the rates of renal hypertension showed a significant downward trend from 2013 to 2016 (P < 0.001). In contrast, OSAS, endocrine hypertension, renal vascular disease, and aorta diseases maintained a significant upward trend from 2013 to 2016 (P < 0.001). The rates of these diseases in women with common secondary hypertension was higher than that of men, except in patients with OSAS (P < 0.001). In addition, renal parenchymal diseases and renal vascular diseases gradually decreased with age, whereas OSAS and aortic diseases gradually increased with age. The proportion of endocrine hypertension in the middle-aged group was higher than the other two age groups.

CONCLUSION

The study provides important information on the changing trends of cause rate of secondary hypertension modified by age and sex in China during 2013-2016. Renal parenchymal disease is still the most common cause of secondary hypertension with a decreasing trend, followed by OSAS with an increasing trend.