Sidsel Graff-Iversen

Non-fasting serum triglyceride concentration and mortality from coronary heart disease and any cause in middle aged Norwegian women.

OBJECTIVE--To study the association between non-fasting serum triglyceride concentrations and mortality in women from coronary and cardiovascular disease and all causes. DESIGN--Follow up by ambulatory teams of men and women who underwent cardiovascular screening for a mean of 14.6 years. SETTING--National health screening service in Norway. SUBJECTS--25,058 men and 24,535 women aged 35-49 years. MAIN OUTCOME MEASURE--Predictive value of non-fasting serum triglyceride concentrations. RESULTS--At initial screening total serum cholesterol concentration, serum triglyceride concentration, blood pressure, height, and weight were measured, and self reported information about smoking habits, physical activity, and time since last meal were recorded. During subsequent follow up 108 women died from coronary heart disease, 238 from cardiovascular diseases, and 931 from all causes. In women mortality increased steadily with increasing triglyceride concentration for all three causes of death. With the proportional hazards model and adjustment for age, systolic blood pressure, total cholesterol concentration, time since last meal, and number of cigarettes a day the relative risk between triglyceride concentration > or = 3.5 mmol/l and < 1.5 mmol/l was 4.7 (95% confidence interval 2.5 to 8.9) for deaths from coronary heart disease, 3.0 (1.9 to 4.8) for deaths from cardiovascular disease, 2.3 (1.8 to 2.9) for total deaths in all women. CONCLUSIONS--A raised non-fasting concentration of triglycerides is an independent risk factor for mortality from coronary heart disease, cardiovascular disease, and any cause mortality among middle aged Norwegian women in contrast to what is seen in men.

Ethnicity and sex are strong determinants of diabetes in an urban Western society: implications for prevention

Aims/hypothesisThis study was conducted to investigate the prevalence of diabetes and its association with ethnicity and sex, to identify subgroups at special risk.MethodsWe performed a population-based cross-sectional survey of 30- to 67-year-olds in an area of Oslo with low socio-economic status, and collected data using questionnaires, physical examinations and serum analyses for the 2,513 participants (attendance rate 49.3%).ResultsIn the age group 30–59 years, mean BMI was 28.5 (95% CI: 27.5–29.6) for South Asian women, 26.1 (25.9–26.4) for Western women, 26.7 (26.1–27.4) for South Asian men and 27.2 (26.9–27.5) for Western men. The diabetes prevalence rates were 27.5% (18.1–36.9) for South Asian women, 2.9% (1.9–3.4) for Western women, 14.3% (8.0–20.7) for South Asian men and 5.9% (4.2–7.5) for Western men. The age-adjusted odds ratio (OR) for diabetes for women vs men was 1.9 (0.9–4.1) for South Asians, and 0.4 (0.3–0.6) for the Western population (p<0.001). The age-adjusted OR for diabetes for South Asians vs Westerners was 11.0 (5.8–21.1) for women and 3.0 (1.6–5.4) for men, and after adjustment for WHR the ORs were 7.7 (3.9–15.3) for women and 2.6 (1.4–4.9) for men. After additional adjustments for physical activity, education, body height and fertility for women, the OR was 6.0 (2.3–15.4) for women and 1.9 (0.9–4.0) for men.Conclusions/interpretationThe alarmingly high prevalence of diabetes among South Asian women in Norway needs further investigation, as it has considerable public health implications. Ethnic differences in OR for diabetes persisted after adjustment for age, adiposity, physical activity and education. These differences were still present for women after additional adjustment for body height and fertility.

Educational inequalities in mortality over four decades in Norway: prospective study of middle aged men and women followed for cause specific mortality, 1960-2000.

Objectives To determine the extent to which educational inequalities in relation to mortality widened in Norway during 1960-2000 and which causes of death were the main drivers of this disparity. Design Nationally representative prospective study. Setting Four cohorts of the Norwegian population aged 45-64 years in 1960, 1970, 1980, and 1990 and followed up for mortality over 10 years. Participants 359 547 deaths and 32 904 589 person years. Main outcome measures All cause mortality and deaths due to cancer of lung, trachea, or bronchus; other cancer; cardiovascular diseases; suicide; external causes; chronic lower respiratory tract diseases; or other causes. Absolute and relative indices of inequality were used to present differences in mortality by educational level (basic, secondary, and tertiary). Results Mortality fell from the 1960s to the 1990s in all educational groups. At the same time the proportion of adults in the basic education group, with the highest mortality, decreased substantially. As mortality dropped more among those with the highest level of education, inequalities widened. Absolute inequalities in mortality denoting deaths among the basic education groups minus deaths among the high education groups doubled in men and increased by a third in women. This is equivalent to an increase in the slope index of inequality of 105% in men and 32% in women. Inequalities on a relative scale widened more, from 1.33 to 2.24 among men (P=0.01) and from 1.52 to 2.19 among women (P=0.05). Among men, absolute inequalities mainly increased as a result of cardiovascular diseases, lung cancer, and chronic lower respiratory tract diseases. Among women this was mainly due to lung cancer and chronic lower respiratory tract diseases. Unlike the situation in men, absolute inequalities in deaths due to cardiovascular causes narrowed among women. Chronic lower respiratory tract diseases contributed more to the disparities in inequalities among women than among men. Conclusion All educational groups showed a decline in mortality. Nevertheless, and despite the fact that the Norwegian welfare model is based on an egalitarian ideology, educational inequalities in mortality among middle aged people in Norway are substantial and increased during 1960-2000.

Promoting Physical Activity in a Low-Income Multiethnic District: Effects of a Community Intervention Study to Reduce Risk Factors for Type 2 Diabetes and Cardiovascular Disease A community intervention reducing inactivity

OBJECTIVE—The aim was to assess the net effects on risk factors for type 2 diabetes and cardiovascular disease of a community-based 3-year intervention to increase physical activity. RESEARCH DESIGN AND METHODS—A pseudo-experimental cohort design was used to compare changes in risk factors from an intervention and a control district with similar socioeconomic status in Oslo, Norway, using a baseline investigation of 2,950 30- to 67-year-old participants and a follow-up investigation of 1,776 (67% of those eligible, 56% women, 18% non-Western immigrants) participants. A set of theory-based activities to promote physical activity were implemented and tailored toward groups with different psychosocial readiness for change. All results reported are net changes (the difference between changes in the intervention and control districts). At both surveys, the nonfasting serum levels of lipids and glucose were adjusted for time since last meal. RESULTS—The increase in physical activity measured by two self-reported questionnaires was 9.5% (P = 0.008) and 8.1% (P = 0.02), respectively. The proportion who increased their body mass was 14.2% lower in the intervention district (P < 0.001), implying a 50% relative reduction compared with the control district, and was lower across subgroups. Beneficial effects were seen for triglyceride levels (0.16 mmol/l [95% CI 0.06–0.25], P = 0.002), cholesterol–to–HDL cholesterol ratio (0.12 [0.03–0.20], P = 0.007), systolic blood pressure (3.6 mmHg [2.2–4.8], P < 0.001), and for men also in glucose levels (0.35 mmol/l [0.03–0.67], P = 0.03). The net proportion who were quitting smoking was 2.9% (0.1–5.7, P = 0.043). CONCLUSIONS—Through a theory-driven, low-cost, population-based intervention program, we observed an increase in physical activity levels, reduced weight gain, and beneficial changes in other risk factors for type 2 diabetes and cardiovascular disease.

Resting heart rate and physical activity as risk factors for lone atrial fibrillation: a prospective study of 309 540 men and women

Objective To study the impact of resting heart rate and leisure time physical activity at middle age on long term risk of drug treated lone atrial fibrillation (AF). Design Longitudinal cohort study of 309 540 Norwegian men and women aged 40–45 years examined during 1985–1999 followed from 2005 through 2009. Setting Data from a national health screening programme were linked to the Norwegian Prescription Database (NorPD). Patients The cohort comprised 162 078 women and 147 462 men; 575 (0.4%) men and 288 women (0.2%) received flecainide and 568 men and 256 women sotalol and were defined as patients with AF. Interventions No interventions. Main outcome measures The outcome was lone fibrillation defined by having at least one prescription of flecainide or sotalol registered in NorPD between 2005 and 2009. Cox proportional hazard regression models were used to assess time to first prescription. Results The risk for being prescribed these drugs increased with decreasing baseline resting heart. Adjusted hazard ratio (HR) per 10 beats/min decrease in resting heart rate for flecainide prescription was 1.26 in men (95% CI 1.17 to 1.35) and 1.15 (95% CI 1.05 to 1.27) in women. Similar effects were seen for sotalol in men, but not in women. Men who reported intensive physical activity were more often prescribed flecainide than those in the sedentary group (adjusted HR=3.14, 95% CI 2.17 to 4.54). Conclusions This population based study supports the hypothesis that the risk of drug treated lone AF increases with declining resting heart rate in both sexes, and with increasing levels of self-reported physical activity in men.

Early menopause, association with tobacco smoking, coffee consumption and other lifestyle factors: a cross-sectional study.

BackgroundEarly onset of menopause is a risk factor for several health problems. The objective was primarily to investigate the association between early menopause and current, past active and passive smoking. A second aim was to investigate the association between coffee and alcohol consumption and early menopause.MethodsThe present population-based cross-sectional study included a sub-sample of 2123 postmenopausal women born in 1940–41 who participated in the Oslo Health Study. Early menopause was defined as menopause occurring at an age of less than 45 years. We applied logistic regression analyses (crude and adjusted odds ratio (OR)) to examine the association between early menopause and selected lifestyle factors.ResultsCurrent smoking was significantly associated with early menopause (adj. OR, 1.59; 95% CI, 1.11–2.28). Stopping smoking more than 10 years before menopause considerably reduced the risk of early menopause (adj. OR, 0.13; 95% CI, 0.05–0.33). Total exposure to smoking (the product of number of cigarettes per day and time as a smoker) was positively related to early menopause and, at the highest doses, nearly doubled the odds (adj. OR, 1.93; 95% CI, 1.12–3.30). These data suggest a possible dose-response relationship between total exposure to smoking and early menopause, but no dose-response relationship was detected for the other variables examined. We found no significant association of coffee or alcohol consumption with early menopause. Of the lifestyle factors tested, high educational level (adj. OR, 0.50; 95% CI, 0.34–0.72) and high social participation (adj. OR, 0.60, 95% CI, 0.39–0.98) were negatively associated with early menopause.ConclusionThis cross-sectional study shows an association between current smoking and early menopause. The data also suggest that the earlier a woman stops smoking the more protected she is from early menopause. Early menopause was not significantly associated with passive smoking, or alcohol or coffee consumption.

Controlling for High-Density Lipoprotein Cholesterol Does Not Affect the Magnitude of the Relationship Between Alcohol and Coronary Heart Disease

Background— This study tested the hypothesis that moderate alcohol intake exerts its cardioprotective effect mainly through an increase in the serum level of high-density lipoprotein cholesterol. Methods and Results— In the Cohort of Norway (CONOR) study, 149 729 adult participants, recruited from 1994 to 2003, were followed by linkage to the Cause of Death Registry until 2006. At recruitment, questionnaire data on alcohol intake were collected, and the concentration of high-density lipoprotein cholesterol in serum was measured. Using Cox regression, we found that the adjusted hazard ratio for men for dying from coronary heart disease was 0.52 (95% confidence interval, 0.39–0.69) when consuming alcohol more than once a week compared with never or rarely. The ratio changed only slightly, to 0.55 (0.41–0.73), after the regression model included the serum level of high-density cholesterol. For women, the corresponding hazard ratios were 0.62 (0.32–1.23) and 0.68 (0.34–1.34), respectively. Conclusions— Alcohol intake is related to a reduced risk of death from coronary heart disease in the follow-up of a large, population-based Norwegian cohort study with extensive control for confounding factors. Our findings suggest that the serum level of high-density cholesterol is not an important intermediate variable in the possible causal pathway between moderate alcohol intake and coronary heart disease.

An adapted version of the long International Physical Activity Questionnaire (IPAQ-L): construct validity in a low-income, multiethnic population study from Oslo, Norway

BackgroundThe aim was to assess the construct validity characteristics of an adapted version of the long International Physical Activity Questionnaire (IPAQ-L) and report seasonal variations in physical activity (PA).MethodsIn two multiethnic suburbs of Oslo, Norway, all men and women aged 31–67 years (N = 6140) were invited to a survey in 2000, and participants (N = 2950) were re-invited in 2003. Complete IPAQ-L forms were delivered by 2274 baseline participants. We used the first IPAQ-L version, which asks for PA in a usual week with separate answering alternatives for summer and winter. Baseline energy expenditure calculated from IPAQ-L was compared with anthropometrical and biological measurements including maximal aerobic power in a subgroup, and individual changes in PA were compared with changes in these measurements.ResultsVigorous PA within all domains, leisure-time PA (LPA), total PA, and in men occupational PA correlated with waist-to-hip ratio (rho around -0.1, p < 0.05). For vigorous PA and LPA similar correlations were found with triglycerides and high-density lipoprotein-cholesterol (rho 0.1, p < 0.05). LPA was correlated with maximal aerobic power in both sexes with rho 0.2 for total LPA and 0.4 for vigorous LPA (p < 0.01). In men, similar correlations were found for changes in total vigorous PA.The overall energy expenditure reported was 18% higher in summer than in winter. The amount of total and commuting PA in the two seasons were highly correlated with rho values of 0.9 and 0.7, respectively (p < 0.01).ConclusionWeak, but consistent correlations with baseline biological and anthropometrical measurements were found in both sexes, but for changes in PA such a pattern was seen in men only. The total energy expenditure in summer and winter were highly correlated although the absolute volume was higher in summer than in winter.

Changes in physical activity behavior and the development of body mass index during the last 30 years in Norway

Body mass index (BMI; kg/m2) has increased markedly in the last decades. We hypothesized that highly physically active persons both at work and at leisure would be resistant to weight gain. The hypothesis was tested by analyzing Norwegian cross‐sectional data collected in the period 1972–2002. Participants were 214 449 men and 206 136 women (aged 20–70 years). During the last 30 years in men and the last 15 years in women, a systematic larger BMI increase per year was observed in the sedentary [regression coefficients (SE) in men 0.060 (0.004) kg/m2 and women 0.137 (0.012) kg/m2] compared with highly physically active groups [regression coefficients (SE) in men 0.036 (0.00 4) kg/m2, and in women −0.001 (0.039) kg/m2]. Analyses were robust to adjustments for age, smoking and education. There was a larger absolute net increase in the prevalence of obesity among the sedentary compared with persons performing light, moderate or heavy physical activity (PA) at leisure. PA level in women both at work and in leisure was not associated with weight gain during the last decades. This association was less evident among men. Men and women who were lightly, moderately or highly active at leisure were less likely to be obese compared with those who were sedentary.

Effect of Years of Endurance Exercise on Risk of Atrial Fibrillation and Atrial Flutter

Emerging evidence suggests that endurance exercise increases the risk for atrial fibrillation (AF) in men, but few studies have investigated the dose-response relation between exercise and risk for atrial arrhythmias. Both exposure to exercise and reference points vary among studies, and previous studies have not differentiated between AF and atrial flutter. The aim of this study was to assess the risk for atrial arrhythmias by cumulative years of regular endurance exercise in men. To cover the range from physical inactivity to long-term endurance exercise, the study sample in this retrospective cohort study was based on 2 distinct cohorts: male participants in a long-distance cross-country ski race and men from the general population, in total 3,545 men aged ≥ 53 years. Arrhythmia diagnoses were validated by electrocardiograms during review of medical records. Regular endurance exercise was self-reported by questionnaire. A broad range of confounding factors was available for adjustment. The adjusted odds ratios per 10 years of regular endurance exercise were 1.16 (95% confidence interval 1.06 to 1.29) for AF and 1.42 (95% confidence interval 1.20 to 1.69) for atrial flutter. In stratified analyses, the associations were significant in cross-country skiers and in men from the general population. In conclusion, cumulative years of regular endurance exercise were associated with a gradually increased risk for AF and atrial flutter.