Association of common medical comorbidities with early renal damage in the Chinese tropics with essential hypertension

BACKGROUND: Urine albumin/creatinine ratio (UACR) is an important marker of early renal damage (ERD) caused by hypertension. Recent studies showed that blood pressure was a significant inverse association with temperature and climate. The purposes of our study were sought to explore the association of common medical comorbidities with ERD, and find independent risk factors to ERD in Chinese tropics with essential hypertension. METHODS: From January 2018 to December 2019, we assessed UACR in a total of 599 hypertensive Chinese Hainan patients. We defined ERD as a UACR between 30 mg/g and 300 mg/g. We analysed differences between qualitative variables using the chi-squared (χ(2)) test. We calculated correlations between UACR and age, hypertension duration (HD), systolic blood pressure (SBP), and diastolic blood pressure (DBP) using the Spearman’s rho test. To determine the odds ratio (OR), we evaluated binary logistic regression models. RESULTS: Among the 599 patients, 281 (46.9%) were found to have ERD. ERD and factors related to sex, body mass index (BMI), and SBP did not differ significantly (all, p>0.05). Our main findings showed that age, HD, and DBP were associated with ERD (p<0.01, respectively). Furthermore, age ≥ 65 years, HD ≥10 years, DBP ≥ 90 mmHg, SBP ≥ 160 mmHg, and diabetes differed significantly according to ERD status (p < 0.05, respectively). In multivariate analysis using stepwise regression, age (OR = 1.468), DBP (OR = 1.853), and diabetes (OR = 2.031) were significant independent predictors of ERD. The area under the receiver operating characteristic (ROC) curve was 0.677, and the sensitivity and specificity of the optimal cut-off value were 44.5 and 81.1%, respectively. CONCLUSIONS: Common medical comorbidities are associated with ERD; age, DBP, and diabetes are independent risk factors for ERD in patients with essential hypertension who live in the Chinese tropics. Early monitoring of the UACR, as well as control of blood glucose and DBP, can effectively delay ERD.