Baseline characteristics according to the year of screening from 2010 to 2013
The participants’ average age was 65.7 ± 9.7 years, and 50.4% were male. The history of HTN, DM, and hyperlipidemia was 57.8%, 24.2%, and 9%, respectively. Further, among cardiovascular diseases, 4.1% reported cerebral infarction, and 10.9% had cardiac disease. The mean SBP of the participants were 127.8 ± 15.8 mmHg. Additionally, BMI and waist circumferences were 24.4 ± 3.0 kg/m2 and 83.6 ± 8.4 cm, respectively. For kidney function, the serum creatinine was 2.4 ± 3.4 mg/dL, and Modification of Diet in Renal Disease (MDRD) eGFR was 46.0 ± 17.6 ml/min/1.73m2. From 2010 to 2013, the examinee’s age increased from 63.1±9.8 to 68.6±8.9 years, and the proportion of women gradually increased from 49.6% to 54.0%. The prevalence of HTN (from 51% to 30.9%), DM (from 82.7% to 65.7%), and hyperlipidemia (from 94.3% to 84.4%) showed a gradual decreasing pattern. As metabolic factors, the mean level of LDL and high-density lipoprotein (HDL) cholesterol decreased, and GFR increased. (Table 1).
Trajectory analysis of variables with a metabolic component within four years
In trajectory analysis, a mean maintenance level of SBP was 138.9±13.2 mmHg in cluster B and 118.9±10.9 mmHg in cluster A (P<0.001). DBP was maintained at a mean of 84±8.0 mmHg in cluster A, 71.3±7.3 mmHg in cluster B (P<0.001). In lipid profile, TC (167.5±26.6 mg/dL in cluster A, 223.4±33.0 mg/dL in cluster B, P<0.001), TG (118.8±46.1 mg/dL in cluster A, 266.1±116.7 mg/dL in cluster B, P<0.001), and LDL cholesterol (89.9±24.3 mg/dL in cluster A, 139.7±31.2 mg/dL in cluster B, P<0.001) were lower in cluster A than cluster B. BMI was clustered into five groups from A to E in the order of the number of distributions of the participants. Most participants maintained at 22 – 25.9 (BMI cluster A: 24.0±0.8 kg/m²; B: 25.9±0.9 kg/m²; C:22.1±0.9 kg/m²; D: 28.2±1.1 kg/m²; E: 19.6±1.3 kg/m²; F: 31.9±2.2 kg/m², P<0.001, respectively) and it was 19.6±1.3 kg/m² at a value close to the criterion of underweight in BMI cluster E group. (Fig 1).
Difference comparison for cluster groups according to all-cause mortality
A total of 307 deaths occurred in clusters A and B from 2010 to 2013. Among the deceased, 233 cases (75.9%) were screened once during the study period. Ten cases (3.3%) had a screening interval of 1 year, 58 cases (18.9%) of 2 years, and six cases (2.0%) of 3 years. In survivors compared to the deceased, the proportion of participants who received screening only once during the study period was low and there were more cases where the screening interval was once a year. The difference in cluster group distribution between the deceased and survivor was compared; among the cluster variables, SBP, DBP, TC, and TG were not significantly different. Proportions of BMI cluster E was more in the deceased (event-free group: Cluster E 9.4%; event group cluster E 20.5%, respectively) (Table 2).
Difference comparison for cluster groups according to the decline of eGFR
There was no difference in the number of deaths in the GFR decrement group compared to the non-GFR decrement group. The interval between most participants’ health screens was two years (59.2% in the non-GFR decrement group, 62.8% in the GFR decrement group). In the group with decreased renal function, eGFR change was 4.7 ± 6.9 ml/min/1.73m2. Among the metabolic components, the proportions of SBP cluster B were 46.9% and 48.5%, respectively, which was higher in the GFR decrement group. The proportions of DBP cluster B were higher in the GFR decrement group (47.7% and 49.3%, respectively). In the GFR decrement group, TG cluster B were 20.9%, which was higher than the non-GFR decrement group. As for other factors, there was no significant difference between the two groups (Table 3).
Regression analysis for events using clustering variables
In logistic regression analysis, SBP cluster B and BMI cluster E were associated with all-cause mortality (SBP cluster B: OR 1.823, 95% CI 1.066-1.212, P = 0.027; BMI cluster E: OR 2.194, 95% CI 1.071-1.4.387, P = 0.027). Factors related to GFR decline included SBP cluster B (HR 1.130, 95% CI 1.066-1.212, P < 0.001), DBP cluster B (HR 1.105, 95% CI 1.036-1.178, P = 0.002), TG cluster A (OR 1.151, 95% CI 1.069-1.240, P < 0.001) showed a significant correlation (Table 4). In multivariable Cox regression analysis, it was not observed to increase in the hazard ratios in cluster B group according to the metabolic component except for BMI (Fig 2). However, we found a lower risk of mortality (HR 0.35, 95% CI 0.15-0.83) in the cluster D (BMI 28.2±1.1 kg/m²) compared to the cluster A (24.0±0.8 kg/m²) (Table 4).