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Given a passage, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

We aimed to study the association between cytomegalovirus (CMV) infection and hypertension in Kazakh and Han populations from Xinjiang Province, China.', 'We analyzed data on 800 Kazakhs (467 hypertension patients and 333 healthy control participants) and 800 Hans (482 hypertension patients and 318 healthy control participants) aged 18-84 years old. ELISA and real-time quantitative PCR coupled with restriction fragment length polymorphism analysis were applied for determining CMV infection and glycoprotein B (gB) genotypes, respectively.', 'Serologic evidence of CMV infection was obtained for 95.4% and 90.1% of the Kazakhs and Hans, respectively. The CMV seroprevalence rates among the Kazakh and Han participants with hypertension were 96.8% and 89.8%, respectively. Multiple logistic regression analyses revealed statistically significant independent associations between CMV seropositivity and hypertension in Kazakh males and between CMV antibody titers and hypertension in Hans; significant relationships also existed between CMV antibody titers and blood pressure in Hans. In Kazakhs, 3 CMV gB genotypes were identified: gB2 and genotype mixtures gB1+gB2 and gB2+gB3. In Hans, 4 CMV gB genotypes were identified: gB1, gB2, gB1+gB2, and gB2+gB3. Of the 4 studied genotypes, gB2+gB3 showed a significant independent association with hypertension in Kazakh females.
Output:
Is human cytomegalovirus infection associated with essential hypertension in Kazakh and Han Chinese populations?