24-hour blood pressure in Uygur, Kazakh and Han elderly subjects in China.

The Uygur in Hotan (Xinjiang, China) are reported to have a long life expectancy. The purpose of this study was to clarify the relationship between variations in blood pressure (BP) and longevity. Cross-sectional surveillance was carried out in both Hotan and Barkol. The subjects were divided into five groups: 1. Uygur longevity subjects in Hotan (103 subjects, age >90 yr); 2. Uygur elderly subjects in Hotan (107 subjects, age 65-70 yr); 3. Han elderly subjects in Hotan (41 subjects, age 65-70 yr); 4. Kazakh elderly subjects in Barkol (117 subjects, age 65-70 yr); 5. Han elderly subjects in Barkol (50 subjects, age 65-70 yr). BP was monitored and analyzed using the fourteen devices of ambulatory BP monitoring. The prevalence of hypertension was lowest in the Uygur (16.2% in Uygur elderly subjects in Hotan; 23.7% in Uygur longevity subjects in Hotan; 27.0% in Han elderly subjects in Hotan; 42.0% in Han elderly subjects in Barkol; 50.0% in Kazakh elderly subjects in Barkol). The ratio of dips in BP was largest in the Han (57% in Han elderly subjects in Barkol; 50% in Han elderly subjects in Hotan; 50% in Uygur longevity subjects in Hotan, 49% in Uygur elderly subjects in Hotan; 17% in Kazakh elderly subjects in Barkol). The 24-h mean systolic BP in Uygur longevity subjects in Hotan was not different from those in Uygur elderly subjects and Han elderly subjects in Hotan, nor did the 24-h mean diastolic BP differ from those in Uygur elderly subjects and Han elderly subjects in Hotan respectively. In conclusion, Uygur subjects seem to be less hypertensive, compared to Kazakh subjects. Uygur longevity subjects had more dipping in their BP variation than did the Kazakh subjects in Xinjiang, China.