A comparison of employment rates of patients treated with continuous ambulatory peritoneal dialysis vs in-center hemodialysis (Michigan End-Stage Renal Disease Study).

This study examines factors associated with employment status in a stratified subsample of the Michigan End-Stage Renal Disease Study population. To reduce the variation in employment potential, the subsample consisted of nondiabetic patients aged 20 to 64 years. The patients were stratified on the basis of their treatment histories as follows: (1) treated by in-center hemodialysis only; (2) primarily treated by continuous ambulatory peritoneal dialysis; and (3) failed continuous ambulatory peritoneal dialysis, substituted by another form of dialysis. A significantly higher percentage of the patients undergoing stable continuous ambulatory peritoneal dialysis were in the labor force than were those undergoing in-center hemodialysis (27.4% vs 9.6%). Using logistic regression, even when adjusted for sex, race, age, education, marital status, primary diagnosis, and duration of end-stage renal disease, the stable continuous ambulatory peritoneal dialysis group was significantly more likely to be employed than the group undergoing either in-center hemodialysis only or the group that failed continuous ambulatory peritoneal dialysis.

Cigarette smoking and neuropathy in diabetic patients.

We studied whether lifetime cigarette smoking is associated with the presence of diabetic neuropathy. The research design consisted of a case-control study conducted from a referral-based diabetes clinic at a major medical center. The patients were a 65% sample (163 insulin-dependent diabetes mellitus [IDDM] and 166 non-insulin-dependent diabetes mellitus [NIDDM] patients) of all patients admitted during a 26-mo period. Neuropathy was diagnosed on the basis of signs and symptoms. Smoking history was obtained by mailed questionnaire (66% response rate). Diabetes duration, HbA1, age, sex, peripheral vascular disease, hypertension history, and lifetime alcohol consumption were measured as covariates. The prevalence of neuropathy was 49 and 38% in IDDM (n = 113) and NIDDM (n = 104) patients, respectively. In IDDM, but not NIDDM, current or ex-smokers were significantly more likely to have neuropathy than individuals who had never smoked (odds ratio 2.46, P = 0.02), and the prevalence of neuropathy increased with increasing number of pack-years smoked (P less than 0.001). After adjustment for covariates, IDDM patients smoking greater than or equal to 30 pack-yr were 3.32 times more likely to have neuropathy than patients smoking less than this amount (95% confidence interval 1.15-9.58, P = 0.026). Cigarette smoking was associated with the presence of neuropathy in this clinic-based population of IDDM patients. The hypothesis that cigarette smoking is associated with diabetic neuropathy should be investigated further, both prospectively and in a more representative population.

Evidence against functional differences between "central" and "peripheral" fat.

As shown in 1639 men and 1851 women in the 20-49 y age range, four commonly used skinfold measurements (triceps, subscapular, iliac, and abdominal) are all highly covariant and do not show clear evidence of upper-body and lower-body or central and peripheral groupings. Moreover, the four skinfold measurements are similarly related to systolic and diastolic blood pressures and to total serum cholesterol at each decile of skinfold thickness and to a degree that strikingly parallels summed skinfold thickness (sigma sf). The changing relative contributions of the different skinfold measurements to the summed skinfold thicknesses with increasing levels of fatness also reveal no evidence of consistent anatomical or topographical groupings by body segment or distance from the body core.

Fatness and obesity of the parents of obese individuals.

As shown in 1419 pairings of obese probands with their parents drawn from a larger series of greater than 9000 proband-parent pairings, the fathers and mothers of obese probands are of increased fatness level (+0.27 Z scores) and more often obese than expected (odds ratio 1.50 overall). However, the tendency towards increased fatness and a greater prevalence of obesity among the parents of obese probands bears a curvilinear relationship to the age of the proband, being least when the probands are young, peaking when the sons and daughters are teen-agers, and declining thereafter. Parents of lean probands in turn tend to be lean themselves (averaging -0.25 Z scores) and least often obese when their progeny are teen-aged. As shown in a two-generational context, familial obesity is best demonstrated in adolescents and their parents, either reflecting years spent in common or a specific etiology for adolescent-onset obesity.

Maturational timing as a factor in female fatness and obesity.

As shown in more than 16 000 white participants in two major studies, menarcheal timing is a major determinant of weight and fatness in early adulthood. Early-maturing women are slightly shorter than late-maturing women but weigh 4 kg more. Early maturers are 30% fatter than late maturers, approximately +0.46 Z scores for each of four different skinfolds. Early maturers are far more often obese than late maturers (risk ratio = 1.8). The data suggest that maturational timing has a greater long-term effect on the level of fatness than the level of fatness had on maturational timing.

The bony chest breadth as a frame size standard in nutritional assessment.

As shown in 2201 males from western Scotland, the roentgenogrammetric bony chest breadth measurements provide a useful indication of frame size. Bony chest breadth is more highly correlated with weight than is true for stature. Weight corrections approximate 3.7 kg/cm of bony chest breadth and weight differences of 12 kg separate the average weight of males in the "small," "medium," and "large" bony chest breadth categories, respectively. Virtually unrelated to fatness per se, the bony chest breadth measurement provides a useful indication of fat free mass and, expressed as the weight/bony chest breadth ratio, it provides an independent estimate of relative fatness. Differences in frame size as measured by the bony chest breadth also relate to the 16-yr cardiovascular mortality.

Educational level, fatness, and fatness differences between husbands and wives.

In 1017 husband-wife pairs aged 20-49 y, both fatness and weight of the wives is inversely and linearly related to educational level whereas the husbands' summed skinfold measurements bear a curvilinear, parabolic relationship to years of schooling. Overall, fatness differences between husbands and wives diminish with increased education, and beyond 13 y of education husbands often exceed the subcutaneous fat thickness of their wives. When the education of one spouse is held constant at 9-12 y, women who marry up to men of greater education are systematically leaner and women who mary down are both fatter and heavier. These findings in spouse pairs sharing a common family income suggest that assortative mating with respect to educational level accounts for much of the socioeconomic effect in fatness including the fatness differences between women who marry down and those who marry up. These data also demonstrate that women are not fatter than men at all socioeconomic levels.

Fatness and mortality in the West of Scotland.

Sixteen-yr mortality data for 2381 males between the ages of 45 to 75 from the West of Scotland show that the lean rather than the obese have a higher mortality rate. However, analyzed by cause of death, it is seen that lean individuals show an excess of cancer-related deaths while obese individuals show excess cardiovascular mortality. Comparing smoking and nonsmoking males, the deleterious effects of smoking are clearly demonstrable at all fatness levels. Since obese males have a higher cardiovascular mortality and lean males show an excess of cancer-related deaths, the notion of a single "ideal weight" may be challenged.

Mortality in patients of the Glasgow Blood Pressure Clinic.

The mortality of 3783 non-malignant hypertensive patients attending the Glasgow Blood Pressure Clinic between 1968 and 1983 and followed for an average of 6.5 years was compared with that in three control groups: the general population of Strathclyde a group of 15 422 subjects aged 45-64 years and screened in Renfrew and Paisley between 1972 and 1976, and a group of hypertensives seen in a blood pressure clinic based on general practice in Renfrew. Average blood pressure for men at entry to the Glasgow Clinic was 181/111 mmHg falling to 158/96 mmHg during treatment. Corresponding values for women were 185/109 mmHg and 161/96 mmHg. Seven hundred and fifty clinic patients (451 males) died during follow-up, the commonest causes of death in both sexes being myocardial infarction and stroke. All-cause age-adjusted mortality (deaths per 1000 patient-years) was 41.4 for men and 22.1 for women. At all ages in both sexes and for all levels of initial blood pressure mortality was less in patients whose blood pressure was reduced most. Without a randomized control group it is not certain that lower mortality in those with well controlled blood pressure was due to treatment, although this is the most likely explanation. Cigarette smoking, a history of myocardial infarction, angina or stroke, retinal arterio-venous nipping, raised blood urea, an abnormal electrocardiogram (ECG) and secondary hypertension were associated with increased risk, but heavy alcohol intake, obesity, haematocrit greater than 45%, hypokalaemia and social class were not. Life table analysis showed that, despite some reduction of mortality by treatment, the relative risk to men and women in the clinic remained two- to five-times that of the general population. The benefits of treatment were not such as to restore normal expectation of life even when blood pressure was well controlled. Excess mortality in the clinic could not be explained by difference of smoking habit or social class. This suggests that there is in the hypertensive patients of the Glasgow Clinic an element of irreducible risk, that treatment may be beneficial in some respects but harmful in others, or that patients at particularly high risk are selectively referred to the clinic.

The charges for ESRD treatment of diabetics.

To evaluate the differential charges for treating end-stage renal disease (ESRD) associated with diabetes mellitus, Medicare billing data are analyzed. The charges of 244 patients in the Michigan Kidney Registry identified as having (ESRD) from diabetes are compared with charges of 902 nondiabetic patients. Average annual charges for ESRD treatment for diabetics are +29,671 (+/- 27,662) which are +4695 (+/- 1344) higher than charges for nondiabetics. The majority of the difference (84.3%) is attributable to higher inpatient hospital charges. Most of the remainder (14.5%) is attributable to higher physician and medical supply charges. Charges for treatment of diabetics are higher on all modalities of treatment, but differences are not significant among modalities.

Characteristics of individuals and long term reproducibility of dietary reports: the Tecumseh Diet Methodology Study.

Food frequency reports in 1967-1969 were compared to frequency reports of the same foods asked retrospectively in 1982-1983 and 1967-1969 for 1184 respondents aged 45-64 years in the Tecumseh Community Health Study. The kappa statistic for concordance of the retrospective and baseline reports was used as a summary measure of the individual's ability to reproduce his or her earlier diet report. Reproducibility was estimated for total diet, represented by 83 foods, and for 9 subsets of foods of epidemiologic interest. In bivariate and multivariate analyses, reproducibility was strongly related to stability of diet; those whose diets changed least over the 15-year period had greatest diet reproducibility. Greater total diet reproducibility was also found among men with higher education, among women of less than 110% desirable weight reporting no special diet and among women reporting no medications. Consistent with current models of memory, the retrospective report of diet was strongly related to the current report of diet. Agreement between the retrospective and baseline diet reports was greater than agreement between the current and baseline diet reports. This indicates that, as a proxy for past diet, the retrospective report of diet is superior to the current report. Similar relationships were found for the 9 subset of foods.

Comparison of surrogate and subject reports of dietary practices, smoking habits and weight among married couples in the Tecumseh Diet Methodology Study.

Agreement between surrogate and subject reports of current food frequencies and other eating habits, smoking behavior and weight was assessed in 1982-1983 for 180 husbands and wives, aged 45 through 64 years. Agreement was measured by per cent exact agreement and weighted kappa for frequencies of 30 itemized foods or food groups, and for surrogate- and subject-based quintiles of frequencies of eight broad food groups and of vitamin A and C consumption indexes. Surrogate and subject mean frequencies were generally similar, but at the individual level of analysis, agreement varied widely. Agreement was greatest, among the food items and groups, for alcoholic beverages, and among the other items, for smoking status. Extreme misclassification by quintile was very small, but only 40% of persons self-classified in either extreme quintile were similarly classified by their spouses. This level of misclassification may result in the dilution of real relationships between diet and health.

Prevalence of radiologically defined osteoarthritis in the finger and wrist joints of adult residents of Tecumseh, Michigan, 1962-65.

Radiographs of the fingers and wrists of adult participants in the Tecumseh Community Health Study in 1962-65 were examined for signs of osteoarthritis (OA). The severity of OA for each of 32 joints of the fingers and wrists was recorded for each individual. Attention was restricted to the 3035 participants who were 32 years of age or older and for whom a diagnosis of OA was available for each of 32 joints. Joint-specific prevalence rates of OA increased sharply with age for both sexes, and at the older ages, the prevalence rates for most joints were higher for females. Older individuals with OA also had a greater number of affected joints, with females having a greater number of affected joints than males. Of those individuals aged 44 years or younger, only 6.2% had one or more joints affected with OA. The percentages were 21.6 and 42.0% for those aged 45-59 years and 60 or more years, respectively. The distal interphalangeal (DIP) joints were the most frequently affected joints in all age categories for both sexes and OA in the proximal interphalangeal (PIP) joints was positively associated with OA in the DIP joints. However, controlling for the number of affected DIP joints, the PIP joints of older subjects were more likely to exhibit OA than the PIP joints of younger subjects. Though there is an association between OA in the DIP and PIP joints, there was only a small, nonsignificant association (OR = 1.24, 95% CI = 0.83, 1.84) between disease in the DIP and PIP joints of the same finger.

Pre-existing ischaemic heart disease and ischaemic heart disease mortality in women compared with men.

BACKGROUND: In all 8353 women and 7058 men aged 45-64 took part in the Renfrew/Paisley survey in 1972-1976. They formed a prospective cohort study of a general population in the West of Scotland; an area with high ischaemic heart disease (IHD) mortality rates. The objective of this study was to investigate three indicators of pre-existing IHD and determine how they predicted subsequent IHD mortality in females compared with males. METHODS: Pre-existing IHD was ascertained by the Rose Angina questionnaire, a question on severe chest pain indicating evidence of previous IHD and an electrocardiogram at a screening examination. Mortality information for a 15-year follow-up period was available. RESULTS: Pre-existing IHD was higher at older ages and was less common in women than men. The risks of IHD mortality were doubled for those with a single cardiovascular indicator compared to those without, and were increased to fourfold for those with two or more indicators. Indicators of pre-existing IHD had high specificity and low sensitivity for subsequent IHD mortality in both women and men, and the positive predictive values for women in the oldest age group were similar to those for men in the youngest age group. CONCLUSIONS: Each indicator of pre-existing IHD was a useful predictor of subsequent IHD mortality in both women and men, even though IHD mortality rates were lower in women. The indicators obtained by questionnaire could be implemented in the primary health care setting to identify quickly those at risk who would benefit from further investigation and intervention.

Breathlessness, chronic bronchitis and reduced pulmonary function as predictors of cardiovascular disease mortality among men in England, Scotland and the United States.

Relationships between cardiovascular disease (CVD) mortality and breathlessness, a definition of chronic bronchitis, and pulmonary function are investigated among men in two employed populations (17,717 London civil servants and 4904 Scottish workers) and in two communities (844 men in Tecumseh, Michigan and 6859 men in Renfrew and Paisley Burghs, Scotland). Men are aged 40-64 years at entry in all studies except Renfrew-Paisley, where they are aged 45-64 years. Length of follow-up ranges from 6 to 16 years. Age and smoking habits were controlled for in all analyses. Chronic phlegm production is not significantly associated with CVD mortality, and 'chronic bronchitis' is significantly associated with mortality only in the employed populations. Low FEV1 is significantly associated with CVD mortality only in the Whitehall study; however, the rate ratios are above one in all studies. Breathlessness is significantly associated with CVD mortality in all studies. These associations between CVD mortality and 'chronic bronchitis', low FEV1, and breathlessness persist after also controlling for employment grade, systolic blood pressure, antihypertensive medication, ECG changes, plasma cholesterol level, body mass index and diabetes. Only the associations between breathlessness and mortality persist after further controlling for low FEV1 and myocardial ischaemia. The rate ratios between breathlessness and mortality are about two for all studies. It is concluded that in these populations, breathlessness is an independent and major predictor of CVD mortality.

Social class differences in lung cancer mortality: risk factor explanations using two Scottish cohort studies.

BACKGROUND: The study investigated differences in lung cancer mortality risk between social classes. METHODS: Twenty years of mortality follow-up were analysed in 7052 men and 8354 women from the Renfrew/Paisley general population study and 4021 working men from the Collaborative study. RESULTS: More manual than non-manual men and women smoked, reported morning phlegm, had worse lung function and lived in more deprived areas. Lung cancer mortality rates were higher in manual than non-manual men and women. Significantly higher lung cancer mortality risks were seen for manual compared to non-manual workers when adjusting for age only and adjustment for smoking reduced these risks to 1.41 (95% CI : 1.12-1.77) for men in the Renfrew/Paisley study, 1.28 (95% CI : 0.94-1.75) for women in the Renfrew/Paisley study and 1.43 (95% CI : 1.02-2.01) for men in the Collaborative study. Adjustment for lung function, phlegm and deprivation category attenuated the risks which were of borderline significance for men in the Renfrew/Paisley study and non significant for women in the Renfrew/Paisley study and men in the Collaborative study. Adding extra socioeconomic variables, available in the Collaborative study only, reduced the difference between the manual and non-manual social classes completely. CONCLUSIONS: There is a difference in lung cancer risk between social classes, in addition to the effect of smoking. This can be explained by poor lung health, deprivation and poor socioeconomic conditions throughout life. As well as anti-smoking measures, reducing socioeconomic inequalities and targeting individuals with poor lung function for help with smoking cessation could help reduce future lung cancer incidence and mortality.

Cigarette smoking and male lung cancer in an area of very high incidence. II. Report of a general population cohort study in the West of Scotland.

A general population cohort of 7055 men aged 45-64 and resident in Renfrew and Paisley, two urban burghs in the West of Scotland, has been followed for 10 1/2 years. Analysis of the cigarette smoking and lung cancer (incidence and mortality) relation has been undertaken in order to establish whether unusual results found in a case-control study of cigarette smoking and lung cancer in the adjacent city of Glasgow could be confirmed. Lung cancer incidence and mortality rates increased markedly for exposure categories up to an average consumption of 15-24 cigarettes per day. Above this level the rates increased only marginally. Expressing these rates relative to that estimated for the never-smoked group and comparing them with the relative risks estimated in the case-control study revealed a similarity in terms of both the shape and the level of the dose-response relation. Comparison of the lung cancer rates found in this cohort with those observed in other cohort studies in the literature (UK doctors, US Veterans, and American Cancer Society volunteers) suggested that the West of Scotland rates were substantially higher at all levels of cigarette exposure.

Individual social class, area-based deprivation, cardiovascular disease risk factors, and mortality: the Renfrew and Paisley Study.

OBJECTIVE: To investigate the associations of individual and area-based socioeconomic indicators with cardiovascular disease risk factors and mortality. DESIGN: Prospective study. SETTING: The towns of Renfrew and Paisley in the west of Scotland. PARTICIPANTS: 6961 men and 7991 women included in a population-based cardiovascular disease screening study between 1972 and 1976. MAIN OUTCOME MEASURES: Cardiovascular disease risk factors and cardiorespiratory morbidity at the time of screening: 15 year mortality from all causes and cardiovascular disease. RESULTS: Both the area-based deprivation indicator and individual social class were associated with generally less favourable profiles of cardiovascular disease risk factors at the time of the baseline screening examinations. The exception was plasma cholesterol concentration, which was lower for men and women in manual social class groups. Independent contributions of area-based deprivation and individual social class were generally seen with respect to risk factors and morbidity. All cause and cardiovascular disease mortality rates were both inversely associated with socioeconomic position whether indexed by area-based deprivation or social class. The area-based and individual socioeconomic indicators made independent contributions to mortality risk. CONCLUSIONS: Individually assigned and area-based socioeconomic indicators make independent contributions to several important health outcomes. The degree of inequalities in health that exist will not be demonstrated in studies using only one category of indicator. Similarly, adjustment for confounding by socioeconomic position in aetiological epidemiological studies will be inadequate if only one level of indicator is used. Policies aimed at reducing socioeconomic differentials in health should pay attention to the characteristics of the areas in which people live as well as the characteristics of the people who live in these areas.

Height and risk of death among men and women: aetiological implications of associations with cardiorespiratory disease and cancer mortality.

OBJECTIVES: Height is inversely associated with cardiovascular disease mortality risk and has shown variable associations with cancer incidence and mortality. The interpretation of findings from previous studies has been constrained by data limitations. Associations between height and specific causes of death were investigated in a large general population cohort of men and women from the West of Scotland. DESIGN: Prospective observational study. SETTING: Renfrew and Paisley, in the West of Scotland. SUBJECTS: 7052 men and 8354 women aged 45-64 were recruited into a study in Renfrew and Paisley, in the West of Scotland, between 1972 and 1976. Detailed assessments of cardiovascular disease risk factors, morbidity and socioeconomic circumstances were made at baseline. MAIN OUTCOME MEASURES: Deaths during 20 years of follow up classified into specific causes. RESULTS: Over the follow up period 3347 men and 2638 women died. Height is inversely associated with all cause, coronary heart disease, stroke, and respiratory disease mortality among men and women. Adjustment for socioeconomic position and cardiovascular risk factors had little influence on these associations. Height is strongly associated with forced expiratory volume in one second (FEV1) and adjustment for FEV1 considerably attenuated the association between height and cardiorespiratory mortality. Smoking related cancer mortality is not associated with height. The risk of deaths from cancer unrelated to smoking tended to increase with height, particularly for haematopoietic, colorectal and prostate cancers. Stomach cancer mortality was inversely associated with height. Adjustment for socioeconomic position had little influence on these associations. CONCLUSION: Height serves partly as an indicator of socioeconomic circumstances and nutritional status in childhood and this may underlie the inverse associations between height and adulthood cardiorespiratory mortality. Much of the association between height and cardiorespiratory mortality was accounted for by lung function, which is also partly determined by exposures acting in childhood. The inverse association between height and stomach cancer mortality probably reflects Helicobacter pylori infection in childhood resulting in--or being associated with--shorter height. The positive associations between height and several cancers unrelated to smoking could reflect the influence of calorie intake during childhood on the risk of these cancers.

Education and occupational social class: which is the more important indicator of mortality risk?

STUDY OBJECTIVES: In the UK, studies of socioeconomic differentials in mortality have generally relied upon occupational social class as the index of socioeconomic position, while in the US, measures based upon education have been widely used. These two measures have different characteristics; for example, social class can change throughout adult life, while education is unlikely to alter after early adulthood. Therefore different interpretations can be given to the mortality differentials that are seen. The objective of this analysis is to demonstrate the profile of mortality differentials, and the factors underlying these differentials, which are associated with the two socioeconomic measures. DESIGN: Prospective observational study. SETTING: 27 work places in the west of Scotland. PARTICIPANTS: 5749 men aged 35-64 who completed questionnaires and were examined between 1970 and 1973. FINDINGS: At baseline, similar gradients between socioeconomic position and blood pressure, height, lung function, and smoking behaviour were seen, regardless of whether the education or social class measure was used. Manual social class and early termination of full time education were associated with higher blood pressure, shorter height, poorer lung function, and a higher prevalence of smoking. Within education strata, the graded association between smoking and social class remains strong, whereas within social class groups the relation between education and smoking is attenuated. Over 21 years of follow up, 1639 of the men died. Mortality from all causes and from three broad cause of death groups (cardiovascular disease, malignant disease, and other causes) showed similar associations with social class and education. For all cause of death groups, men in manual social classes and men who terminated full time education at an early age had higher death rates. Cardiovascular disease was the cause of death group most strongly associated with education, while the non-cardiovascular non-cancer category was the cause of death group most strongly associated with adulthood social class. The graded association between social class and all cause mortality remains strong and significant within education strata, whereas within social class strata the relation between education and mortality is less clear. CONCLUSIONS: As a single indicator of socioeconomic position occupational social class in adulthood is a better discriminator of socioeconomic differentials in mortality and smoking behaviour than is education. This argues against interpretations that see cultural--rather than material--resources as being the key determinants of socioeconomic differentials in health. The stronger association of education with death from cardiovascular causes than with other causes of death may reflect the function of education as an index of socioeconomic circumstances in early life, which appear to have a particular influence on the risk of cardiovascular disease.