Relationship of metabolic syndrome and number of steps in dailylife among urban elderly in China

Abstract

Objective: With China's rapid economic development, the incldeuce of lifestyle-related diseases has increased and a high prevalence of metabolic syndrome (MS) has been reported. This study investigated the relationship between metabolic syndrome and steps/ day among urban elderly in China by collecting 365 days of continuous self-monitored pedometer data. Materials: We recruited 200 elderly subjects to participate in our study among 9167 community residents aged 65 or more years old who were registered at a community hospital-「WangDingTi Hospital」 in the NANKAI distract in Tianjin City, China. Of these 200 elderly subjects, we analyzed 90 participants who completed questionnaires on lifestyle factors in March 2004, underwent repeated medical checkups in March 2004 and February 2005 as well as recorded pedometer data through out 2004. Methods: All participants received a pedometer (OMRON HJ_002) and were instructed to record total steps per day during their usual activity for any three days per week during waking hours throughout one year. We summed the total steps on any three days per week for one year and then divided the recorded data to determine the average dailylife steps/ day (steps/ day) in this study. MS was diagnosed using the Chinese Diabetes Society 2004 (CDS) criterion. In our study, we called the MS group (50 participants) who were diagnosed as having MS either in March 2004 or in February 2005 and the NON-MS group (40 participants) who were not diagnosed as having MS on either of the two medical checkups. We used SPSS11.0J for statistical analysis. Result: Ninety participants (49 men, 41 women), with a mean age ±SD of 70.2 ±4.6 years showed a mean value of 5509 ±3480 steps/ day, There was a significant difference between the MS group (4811 ±2580 steps/ day) and the NON-MS group (6380 ±4226 steps/ day) (p =0.043). Compared to the number of steps/ day by subjects without any component of MS, that of those with 1-4 MS components was significantly lower (p =0.004). In addition, the steps/ day in the obesity group (BMI ≥25 (Kg/ m²)) was less than that in the normal weight group (BMI <25 (Kg/m²)) (P =0.004), the steps/ day in the high diastolic blood pressure (DBP ≥90mmHg) group was less than that in the DBP <90mmHg group (P =0.045). When we performed categorical analysis using cut off points of 5000, 6000, 7000 and 8000 steps/ day, a cut off point over 6000 steps/ day showed a significant difference between normal weight and obesity group, and a cut off point of 8000 steps/ day showed significant difference between the normal weight and obesity group as well as between the high diastolic blood pressure and normal diastolic blood pressure group, respectively. After using sex and the age-adjusted logistic regression model, the risk of obesity was significantly lower over 5000 steps/ day and the risk of obesity and high diastolic blood pressure were significantly lower over 8000 steps/ day. Moreover, the more components of MS other than BMI, the higher the average BMI became. Conclusion: This study showed that metabolic syndrome was closely associated with the number of daily-life steps/ day among urban elderly in China. In subjects with over 5000 steps/ day, BMI was lower, and in those with over 8000 steps/ day, both BMI and DBP were significantly lower.