High heart rate relates to clustering of cardiovascular risk factors in a screened cohort

Increased heart rate (HR) is a predictor of cardiovascular mortality, so the present study used a screened cohort to investigate whether the clustering of cardiovascular risk factors is associated with increased HR. Individuals who were receiving medication for hypertension or heart disease and those who did not have an ECG record or who had a record of arrhythmia were excluded. In total, 8,508 subjects (5,299 men, 3,209 women; age range, 18-89 years) were studied. Subjects were divided into 2 HR classes using the value of mean HR+ 1 SD as the cut-off point: low HR (HR < 77 beats/min, n=7,320) and high HR (HR > or = 77 beats/min, n=1,188). For logistic regression analysis, the dependent variable was HR class and the independent variables were the number of risk factors (ie, hypertension, diabetes mellitus, and hypertriglyceridemia each of which was associated positively with HR class by multivariate analysis). The odds ratios and 95% confidence intervals for the number of risk factors were 1.412 (1.216-1.640) for 1 risk factor, 2.800 (2.269-3.455) for 2, and 4.582 (2.815-7.459) for 3. Multivariate regression analyses showed that the number of risk factors from 0 to 3 correlated positively with high HR. HR increased significantly with clustering of risk factors even with low HR (regression coefficient was 1.147, p<0.0001). Modifying the risk factors may lower HR and reduce cardiovascular mortality.

Significance of hyperuricemia on the early detection of renal failure in a cohort of screened subjects

A high level of serum creatinine (S-Cr) is a predictor of end-stage renal disease (ESRD), but only a few studies have investigated the prevalence of high S-Cr and its correlates in a large population. We analyzed the data collected from 6,403 subjects (4,222 men and 2,181 women) who participated in the Okinawa General Health Maintenance Association (OGHMA) screening both at 1997 and 1999. The computer-saved data included sex, age, blood chemistries, blood pressure, medical histories, and lifestyles. Multivariate Cox proportional hazard analyses were performed to identify the correlates of developing high S-Cr levels: > or = 1.4 mg/dl in men and > or = 1.2 mg/dl in women. The prevalence of high S-Cr was 3.0% (N=193), which was 4.1% in men (N=175) and 0.8% in women (N=18), and increased with age in both sexes at the 1997 screening. Among those who showed normal levels of S-Cr in 1997 (N=6,210), 241 subjects (223 men and 18 women) developed high S-Cr. The 2-year cumulative incidence of high S-Cr was 5.5% in men and 0.8% in women. Other than sex, serum uric acid was the most significant correlate for developing high S-Cr. The adjusted relative risk (95% confidence interval) of those with serum uric acid 8.0 mg/dl and over was 2.91 (1.79-4.75) in men and 10.39 (1.91-56.62) in women when compared to those with serum uric acid less than 5.0 mg/dl. Prevalence of high levels of S-Cr was relatively high in men. Other than gender, serum uric acid was a significant positive correlate of developing high S-Cr in this sample of the Japanese population.

Family history of hypertension and blood pressure in a screened cohort

We sought to determine whether a family history of hypertension is quantitatively associated with the prevalence of hypertension and blood pressure in a screened cohort. Clinical data and family (parents and siblings) histories regarding hypertension were collected from 9,914 individuals (probands) who were interviewed and examined during a one-day clinic by the Okinawa General Health Maintenance Association in 1997. We used logistic analysis to calculate odds ratios with adjustments for age, sex, body mass index, total cholesterol, presence of diabetes mellitus, alcohol use, cigarette smoking, and status of physical exercise. The age- and sex-adjusted hypertension prevalences in probands were 29.0% for those with 1 family member with a history of hypertension (n=2,112), 37.6% for those with 2 hypertensive family members (n=374), and 47.3% for those with 3 or more hypertensive family members (n=68). In contrast, only 16.4% of probands who reported no family history of hypertension (n=7,360) were hypertensive themselves. The trend of the prevalence according to the number of family members with a history of hypertension was significantly positive (p=0.003). The adjusted odds ratios (95% confidence interval) of hypertension were 2.74 (2.43-3.10) for 1 member, 4.62 (3.62-5.90) for 2 members, and 6.04 (3.51-10.4) for 3 or more members with a history of hypertension. In patients without antihypertensive medication (n=9,009), systolic/diastolic blood pressure (mean +/- SD) was 121 +/- 17/75 +/- 11 for 1 member, 124 +/- 18/77 +/- 12 for 2 members, and 127 +/- 17/78 +/- 11 for 3 or more members with a history of hypertension. In contrast, the mean systolic/diastolic blood pressure of probands who reported no family history of hypertension (n=7,360) was 119 +/- 15/74 +/- 10 mmHg, which was significantly (p<0.05) lower than that of any of the groups with hypertensive family members. In conclusion, an increase in the number of family members with hypertension was associated with an increasing prevalence of hypertension and blood pressure in the probands, independent of conventional risk factors for hypertension. Family members of hypertensive subjects may need to be treated in primary prevention efforts related to hypertension.

Multiple risk factor clustering of hypertension in a screened cohort

OBJECTIVE

A family history of hypertension, obesity, diabetes mellitus, hypercholesterolaemia and hypertriglyceridaemia have all been associated with the risk for hypertension. We evaluated whether the clustering of these risk factors increases the risk for hypertension or whether the accumulation of risk factors is associated with the blood pressure level in non-hypertensive subjects.

METHODS AND SUBJECTS

We assessed the clinical data and family history of hypertension (in parents and siblings) for 9914 individuals (6163 men and 3751 women, 18-89 years old) who were screened in Okinawa, Japan, in 1997.

RESULTS

In 9914 subjects (2465 hypertensive and 7449 non-hypertensive subjects), all the five factors were positively associated with hypertension. The odds ratios (95% confidence interval) for the number of risk factors were 1.88 (1.62-2.18) for one risk factor, 3.06 (2.62-3.57) for two, 5.25 (4.37-6.30) for three, 8.71 (6.48-11.72) for four and 24.48 (8.49-70.56) for five, after adjusting for age, sex, alcohol consumption, cigarette smoking and physical exercise habits. In non-hypertensive subjects, multivariate regression analyses showed that the number of risks was positively correlated with blood pressure; the regression coefficient was 1.96 (P < 0.0001) for systolic blood pressure, and 1.47 (P < 0.0001) for diastolic blood pressure after adjusting for age and sex.

CONCLUSIONS

Clustering of risk factors was significantly associated with hypertension. The number of risk factors positively correlated with the blood pressure levels in nonhypertensive subjects. The accumulation of risk factors may play an important role in the pathogenesis of hypertension, and thus the aggregation of risk factors may need to be addressed in primary prevention efforts related to hypertension.

Comparison of the effect of blood pressure on the development of stroke, acute myocardial infarction, and end-stage renal disease

Hypertension is a known risk factor for cardiovascular disease, but few epidemiological studies have examined simultaneously the effect of baseline blood pressure on the development of stroke, acute myocardial infarction (AMI), and end-stage renal disease (ESRD). In 1983, a large, community-based mass screening covered about 14% of the adult population in Okinawa, Japan. The total number of people screened was 107,192 (51,122 men, 56,070 women). We had access to two independent registries of end-organ damage: the Co-operative Study Group of Morbidity and Mortality of Cardiovascular Diseases in Okinawa (COSMO) registry for stroke and AMI, and the Okinawa Dialysis Study (OKIDS) registry for ESRD. The total number of people registered was 4,756 with stroke, 1,059 with AMI, and 641 with ESRD during the study period from April 1, 1988, to March 31, 1991. By using the name, sex, birth date, and ZIP code of registrants, we identified those registrants who were screened in 1983 and had developed stroke, AMI, or ESRD. Hypertension was defined as systolic blood pressure (SBP) of 140 mmHg or higher or diastolic blood pressure (DBP) of 90 mmHg or higher. Other readings were regarded as normotensive. The prevalence of hypertension was 35.8% (N=37,299). The cumulative incidence of stroke, AMI, and ESRD was 154, 21, and 19 subjects among those with SBP < or = 119 mmHg, and 1933, 315, and 71 subjects among those with SBP > or = 160 mmHg. Similarly, the incidence of stroke, AMI, and ESRD was 234, 44, and 25 subjects among those with DBP < or = 69 mmHg and 1980, 381, and 364 subjects among those with DBP > or = 110 mmHg. Hypertension was prevalent in the adult population in Okinawa, Japan, and was a significant predictor of stroke, AMI, and ESRD. However, the effect of blood pressure on target organs differed and was more evident in those with stroke than in those with AMI and ESRD.

Low serum cholesterol as a risk factor for hemorrhagic stroke in men: a community-based mass screening in Okinawa, Japan

The relation between the level of total serum cholesterol and stroke is controversial. The relation between serum total cholesterol and subtypes of stroke was examined in the participants of a community-based mass screening program in Okinawa, Japan. A total of 38,053 subjects, whose serum level of cholesterol had been determined during a mass screening carried out in 1983, were examined to see whether they had experienced stroke during a 3-year period from 1988 to 1991. Of them, 315 subjects aged 33-93 years (174 men, 141 women) had had a stroke during that period. The types of stroke were cerebral infarction in 164, cerebral hemorrhage in 111, subarachnoid hemorrhage in 19, and others in 21. In men, the odds ratio of cerebral hemorrhage was 0.71 (95% confidence interval, 0.55-0.95), and the odds ratio of cerebral hemorrhage associated with serum level of cholesterol < or =167 mg/dl, 168-191 mg/dl, 192-217mg/dl, and > or =218mg/dl were 1.00 (reference), 0.70 (0.38-1.30), 0.77 (0.55-1.08), 0.73 (0.56-0.96), respectively. Lower serum cholesterol was an independent predictor of cerebral hemorrhage in men.

Relationship between serum cholesterol and the risk of acute myocardial infarction in a screened cohort in Okinawa, Japan

Coronary heart disease (CHD) is rare in Japanese subjects and serum cholesterol levels are low. However, no data have been published relating the effect of serum cholesterol levels to the incidence of acute myocardial infarction (AMI) in Japan. Data from a large community-based mass screening registry are available for the geographically isolated island of Okinawa, Japan (1980 census, 1.11 million). A total of 38,053 participants (17,859 men and 20,194 women) whose serum cholesterol levels were determined in the 1983 mass screening were examined to determine whether they had experienced AMI. Every case of AMI that occurred during a 3-year period (1 April 1988 to March 1991) throughout Okinawa was recorded in a separate registry. The total number of cases of AMI was 1,021 (674 men and 347 women). Of these, 65 patients (41 men and 24 women) were identified by name, sex, birth date, and zip code in the mass screening registry. The cumulative incidence of AMI increased with the serum level of cholesterol: 42.1 (serum cholesterol < or = 167 mg/dl), 133.5 (serum cholesterol 168-191 mg/dl), 188.9 (serum cholesterol 192-217 mg/dl), and 323.0 (serum cholesterol > or = 218 mg/dl) per 100,000 screened subjects. Multiple logistic analysis was conducted to examine the effect of serum cholesterol on the risk of AMI with adjustment for other variables such as sex, age, systolic and diastolic blood pressure, and proteinuria. The adjusted odds ratio (95% confidence interval) of the observed serum levels of cholesterol was 1.66 (1.29-2.15) with a reference serum cholesterol level of < or = 167 mg/dl. The risk of AMI increased in proportion to the serum level of cholesterol. Serum cholesterol is an independent predictor of AMI in Okinawa, Japan.

Predictors of end-stage renal disease and body mass index in a screened cohort

The effect of body mass index (BMI) on the risk of developing end-stage renal disease (ESRD) has not been critically evaluated. To investigate this issue we used the registries of community-based mass screening and chronic dialysis programs. In 1983, a total of 101,516 subjects (47,901 men and 53,615 women) participated in a mass screening program in Okinawa, Japan. A total of 187 (101 men and 86 women) entered an ESRD program by March 31, 1994. Body mass index was calculated as weight in kilograms divided by the square of the height in meters. Subjects were categorized into six groups based on BMI: < 20.0, 20.0-21.9, 22.0-23.9, 24.0-25.9, 26.0-27.9, and > or = 28.0 kg/m2. The cumulative incidence of ESRD, per 100,000 subjects was calculated in each BMI subgroup for men and women. In men, the cumulative incidence of ESRD increased with BMI, except in the range of 24.0 to 25.9 kg/m2. In women, the association between the cumulative incidence of ESRD and BMI was not clear, but was lowest in the range of 24.0 to 25.9 kg/m2. The adjusted odds ratio (95% confidence interval) was 0.99 (0.92 to 1.13) in men and 0.83 (0.72 to 0.96) in women.

Risk factors of end-stage renal disease and serum creatinine in a community-based mass screening

This study evaluated risk factors for end-stage renal disease (ESRD) and the prognostic significance of serum creatinine levels in a community-based mass screening. We used the registries of both community-based mass screening and chronic dialysis programs. In 1983, a total of 107,192 subjects over 18 years of age (51,122 men and 56,070 women) participated in a mass-screening program in Okinawa, Japan. Among them, serum creatinine data were available for 14,609 participants (5,613 men and 8,996 women). During 10 years of follow-up, we identified 60 dialysis patients (29 men and 31 women) among this group. Logistic regression analysis on the risk of ESRD was performed to determine the significance of serum creatinine levels in comparison with other clinical variables. The adjusted odds ratio (95% confidence interval) was 5.31 (3.39 to 8.32) in men and 3.92 (2.88 to 5.34) in women when compared to baseline serum creatinine levels of less than 1.0 mg/dl in women and 1.2 mg/dl in men. Diastolic blood pressure was not a significant predictor of ESRD. Results demonstrated the prognostic significance of serum creatinine in a community-based mass screening. Gender difference in the incidence of ESRD was explained, at least partly, by differences between clinical predictors and baseline serum creatinine levels.

Blood pressure and risk of end-stage renal disease in a screened cohort

We prospectively studied a total of 107,192 subjects over 18 years of age (51,122 men and 56,070 women) who participated in dipstick urinalyses and blood pressure measurements in 1983. The subjects represented approximately 13.7% of the entire Okinawan adult population of 780,000 according to the 1980 Census. Independently, data for all dialysis patients registered from April 1, 1983 to March 31, 1994 were analyzed; the total number of end-stage renal disease (ESRD) dialysis patients was 2,009 (1,126 men and 883 women) during the study period. Dialysis patients who had been in the 1983 mass screening and who later required dialysis during the study period were identified and verified by reviewing the medical records. ESRD developed in 193 (105 men and 88 women) participants from the 1983 health screening. In this mass screening setting, high diastolic blood pressure was identified as the significant predictor of ESRD with an adjusted odds ratio of 1.39 and a 95% confidence interval of 1.17 to 1.64.

Risk of developing end-stage renal disease in a cohort of mass screening

The prognostic significance of abnormal findings has not been demonstrated in a setting of mass screening. To evaluate the relative risk of end-stage renal disease (ESRD) indicated by various results of community-based mass screening, we utilized the registries of both community mass screening and chronic dialysis programs. In 1983, a total of 107,192 subjects over 18 years of age (51,122 men and 56,070 women) participated in dipstick urinalysis and blood pressure measurement in Okinawa, Japan. During ten years of follow-up, we identified 193 dialysis patients (105 men and 88 women) among them. Logistic regression analysis of clinical predictors of ESRD over 10 years was done and the adjusted odds ratio and 95% confidence interval were calculated in each of the predictors with adjustment to others. In the clinical predictors such as sex, age at screening, proteinuria, hematuria, systolic and diastolic blood pressure, proteinuria was the most potent predictor of ESRD (adjusted odds ratio 14.9, 95% confidence interval 10.9 to 20.2), and the next most potent predictor was hematuria (adjusted odds ratio 2.30, 95% confidence interval 1.62 to 3.28). Being of male gender was a significant risk factor for ESRD (adjusted odds ratio 1.41, 95% confidence interval 1.04 to 1.92). Diastolic blood pressure was also a significant predictor of ESRD (adjusted odds ratio 1.39, 95% confidence interval 1.17 to 1.64), but systolic blood pressure was not. In a mass screening setting, positive urine test, high diastolic blood pressure, and male sex were identified as the significant predictors of ESRD. Effect of glycosuria and other possible predictors of ESRD remained to be determined.