The Bowling Green Study of the Primary and Secondary Prevention of Atherosclerotic Disease: Update 1991-1993

This update of the Bowling Green Study (BGS) of the primary and secondary prevention of atherosclerotic disease (ASD) presents additional information to expand the previously published database. Research methodology has not changed. The expanded database now includes the risk factor data for all BGS patients known to have developed some form of clinical ASD from 4 November 1974 to 1 January 1994. The expanded ASD patient database contains data for 267 male and 248 female patients. Plotting the systolic blood pressure (SBP) versus the cholesterol retention fraction (CRF or [LDL-HDL]/LDL, where LDL is low-density lipoprotein cholesterol and HDL is high-density lipoprotein cholesterol) for all ASD patients for whom this information is known revealed that plots for 82% of male and 75% of female patients lie above the ASD threshold line. If only ASD patients less than 80 years of age are considered, then plots for 85% of male and 78% of female ASD patients lie above the ASD threshold line. Considering patients of any age, those whose plots lie above the ASD threshold line comprise the majority (79%) of ASD patients, with the remainder (21%) of ASD patients lying below the line. The area above the ASD threshold line on the BGS Graph defines the CRF-SBP characteristics for 79% of all ASD patients of any age, and for 82% of all ASD patients less than 80 years of age. Since relatively few ASD patients do not exhibit these CRF-SBP characteristics, it is possible to define the population at risk of clinical ASD as those patients whose plots lie above the ASD threshold line and/or those who smoke cigarettes. Conversely, those people whose plots lie below the ASD threshold line and who never smoked cigarettes appear to have a low risk of developing clinical ASD during their lifetimes. OHIO J. SCI. 94 (4): 105-112, 1994 INTRODUCTION The original publication of the Bowling Green Study database (Feeman 1992) presented a table of risk factors for atherosclerotic disease (ASD) of the heart arteries (ASHD), cerebral arteries (ASBD), and peripheral arteries (ASVD) observed between 4 November 1974 to 1 January 1991In the ensuing three years, additional patients have suffered some form of clinical ASD. Tabulation of the risk factors data of these additional patients would be of interest to those investigators studying the causes of ASD. MATERIALS AND METHODS The Bowling Green Study (BGS) of the Primary and Secondaiy Prevention of Clinical ASD is an ongoing investigation. New patients are added daily to the BGS database, and on a less regular basis to the BGS ASD database. The BGS database consists of a private practice of family medicine in Bowling Green, OH, and all new patients are enrolled in the general database. Those who develop some form of clinical ASD and those new patients who have a histoiy of clinical ASD are added to the BGS ASD database. As a result, the BGS general database (4 Nov 74 1 Jan 94) now contains data on 4,758 male and 4,862 female patients, of whom 267 male and 248 female patients have developed some form of clinical ASD. The database of ASD risk factors for those patients who developed clinical ASD prior to 1 January 1991 has been published (Feeman 1992). The database of risk factor data for the 1991-1993 patients are presented in this report (Tables 1-6). 'Manuscript received 15 April 1994 and in revised form 23 August 1994 (=91-08). Data collection methods and measurements have not changed since the original publication. Over time, it has been determined that a few ASD patients who were believed to have ASD on the basis of certain electrophysiological or radiological criteria did not actually have ASD. These patients have been deleted from the ASD database (Appendix I and II). RESULTS With the addition to the database of information published in this report (Tables 1-6), the BGS ASD database contains risk factor data on 218 male and 220 female patients with ASHD, 94 male and 76 female patients with ASBD, and 52 male and 33 female patients with ASVD. Since some patients have more than one type of ASD, there have been 364 male ASD events and 329 female events. This is an extensive database from which to make projections. The usefulness of the BGS Graph in predicting the population at risk for ASD is evident (Table 7). If all the patients in the 1974-1993 ASD database are considered, 82% of male ASD patients of all ages and 75% of female ASD patients of all ages lie above the line, regardless of cigarette smoking or diabetes status. If one considers only patients aged less than 80 years, then 85% of male ASD patients and 78% of ASD female patients lie above the ASD threshold line. Of the patients whose plots lie below the ASD threshold line, 23 are current smokers, 20 are past-smokers, and 21 never-smokers. If only patients aged <79 years are considered, 21 are current-smokers, 12 are past-smokers, and ten are never-smokers. The earlier BGS report showed that cigarette smoking is second only to the CRF as a risk 106 BOWLING GREEN STUDY UPDATE VOL. 94 l: bbreviations used in Tables 1-6 are: C: (lotal cholesterol). I IDL (higlvdensity-lipoprotein cholesterol), LDL (low-tlensity-lipoprotein cholesterol), CRF (Cholesterol Retention Fraction, or [LDL-HDU/LDD, TG (triglycericles), PSI. (plasma sugar level), SBP (systolic blood pressure), DBF (diastolic blood pressure), BMI (body mass index, or Weight [Kg], Height (m)]), 1H (in-hospital data), RX (data after treatment). "D" in the PSL column (known diabetes mellitus), and HXIGT in the PSL column (history of impaired glucose tolerance). The cigarette column abbreviations "+" (current cigarette smoker), past (past cigarette smoker), "-" (never cigarette smoker). A "f" symbol means that the patient has died. A "•" means that the patient has multiple system ASD. AMI (acute myocardial infarction, AP (angina pectoris), CHF (congestive heart failure), HX (history of ASD), and SUD (Sudden Unexpected Death), TCVA (Thrombotic Cerebrobascular Accident), HCVA (Hemorrhagic cerebrovascular accident), TIA (Transient Ischemic Attack), and ACS (asymptomatic carotid stenosis). ASPVD (ASD of the peripheral vasculature), AAA (abdominal aortic aneurysm), TAA (thoracic aortic aneurysm). ASHD means atherosclerotic heart disease, ASBD means atherosclerotic brain disease, and ASVD means atherosclerotic (peripheral) vascular disease. TABLE 1 Male ASHD *-1991 -1993. Age ASHD Type C,. HDL LDL CRF TG PSL Cigarettes SBP DBF BMI OHIO JOURNAL OF SCIENCE W. E. FEEMAN, JR 107 * Abbreviations are the same as in Table 1.