Epidemiology of hip fractures in Oslo, Norway.

The incidence of hip fractures in Oslo has shown a secular increase during the past decades. The main aims of the present study were to report the current incidence of hip fractures in Oslo and to determine whether there is a seasonal variation in the occurrence of fractures. Using the electronic diagnosis registers and the lists of the operating theater for the hospitals in Oslo with somatic care, all patients with ICD-9 code 820.X (hip fracture) from May 1, 1996 to April 30, 1997 were identified. Medical records for all identified patients were obtained and diagnosis was verified. Using the population of Oslo on January 1, 1997 as the population at risk, the age- and gender-specific annual incidence rates were calculated. These rates were compared with those for 1988/89 and 1978/79. Outdoor temperature data for Oslo were obtained to study the relation between temperature and number of hip fractures. A total number of 1316 hip fractures was included, of which 78% occurred in women. An exponential increase in incidence with age was observed in both genders. The age-adjusted fracture rates per 10,000 for the age group > or =50 years were 118.0 and 44.0 in 1996/97, 124.3 and 44.9 in 1988/89, and 104.5 and 35.8 in 1978/79 for women and men, respectively. There was no significant seasonal variation in the incidence of hip fractures and no correlation between mean outdoor temperature and number of fractures for each month in 1996/97. The data show that the incidence of hip fractures in Oslo has not changed significantly during the last decade, and it is still the highest reported. The cold climate of Oslo does not seem to contribute to the high incidence.

More postoperative femoral fractures with the Gamma nail than the sliding screw plate in the treatment of trochanteric fractures.

Despite several studies showing a higher incidence of peri-implant femoral fractures with the Gamma nail than with a sliding screw plate (SSP), the Gamma nail has remained the standard implant for trochanteric fractures in many hospitals. We recorded 921 trochanteric fractures in the city of Oslo during 2 years and compared the reoperation frequency in patients treated with the Gamma nail (n 379) and SSP (n 542). The distribution of age and gender in the two treatment groups was the same. 65 patients were reoperated on, several of them more than once. The only significant difference between the two surgical methods in complications leading to a reoperation was the frequency of femoral shaft fractures. 17 of the patients treated with the Gamma nail had a new femoral fracture postoperatively, compared to 3 of those with a SSP. The relative risk of another femoral fracture after surgery was 12 (95 % CI: 2.7-52) if the surgical device was a Gamma nail compared to a SSP. The Gamma nail therefore can not be recommended as the standard implant for trochanteric fractures.

Differences in cardiovascular disease mortality and major risk factors between districts in Oslo. An ecological analysis.

BACKGROUND: The level of mortality from cardiovascular disease (CVD), coronary heart disease (CHD) and from all causes varies considerably within Oslo. The purpose of this study was to examine these differences according to cardiovascular risk factors and socioeconomic variables at the district level. METHODS: Total mortality rates and cardiovascular mortality rates for subjects aged 45-74 years in 1991-1995, and their relationship to cardiovascular risk factors and socioeconomic indicators in the 25 districts of Oslo were studied. Cardiovascular risk factors were based on data from 40 year olds in 1985-1988. The following variables were used as independent variables in the regression analyses to explain differences between the districts: daily smoking, cholesterol level, systolic blood pressure, education and income. RESULTS: Mortality rates were strongly related to cardiovascular risk factors and to socio-economic indicators, with correlation coefficients (Pearson) of 0.74 for smoking and CVD mortality, and -0.78 for high income and CHD mortality. Smoking explained 70% of the differences in mortality from all causes for men and 46% for women, and 61% and 49% of the differences in CVD mortality for men and women respectively. Diastolic blood pressure and total cholesterol were closely related to socioeconomic indicators and to smoking, but the relative strength of the cardiovascular risk factors in the multivariate analyses differed for males and females. CONCLUSION: diovascular risk factors and socioeconomic indicators at the population level were strongly related to mortality, and explained a large proportion of the differences in mortality between different districts of Oslo in the 1990s.

Adipose tissue fatty acids and risk of myocardial infarction--a case-control study.

OBJECTIVES: To study the association between content in adipose tissue of very long-chain n-3 fatty acids, trans fatty acids, linoleic acid and alpha-linolenic acid and risk of a first myocardial infarction. DESIGN AND SUBJECTS: A case-control design among 100 patients and 98 population controls both men and postmenopausal women, age 45-75 y. Adipose tissue fatty acids were determined by gas-liquid chromatography. Intake data were obtained through interview using a validated food frequency questionnaire. RESULTS: Dietary intake and adipose tissue content of the fatty acids studied correlated significantly. Adipose tissue contents of eicosapentaenoic acid (20:5n-3), docosapentaenoic acid (22:5n-3) and docosahexaenoic acid (22:6n-3) were significantly lower while those of trans fatty acids, linoleic and alpha-linolenic acid were significantly higher in patients than in controls. Age and sex adjusted odds ratios (OR) were significantly reduced with increasing quintiles of very long-chain n-3 fatty acids, thus the OR in the fifth compared to the first quintile was 0.23 (95% CI 0.08-0.70). After further adjustment for waist-to-hip ratio, smoking, family history of CHD and content of trans fatty acids, the OR in the highest quintile was 0.17 (95% CI 0.04-0.76) and the P for trend 0. 016. Age and sex adjusted OR was increased in the fifth compared to the first quintile of trans fatty acids (OR 2.81, 95% CI 1.16-6.84), linoleic acid (OR 2.10, 95% CI 0.87-5.07) and alpha-linolenic acid (OR 1.96, 95% CI 0.83-4.61), and P for trend was 0.002, 0.005 and 0. 020, respectively. The trends remained significant after adjustment for waist-to-hip ratio, smoking, and family history of coronary heart disease. Trans fatty acids, linoleic acid and alpha-linolenic acid in adipose tissue were strongly correlated, indicating a common source, most likely margarine. When each of these fatty acid species were adjusted for the two others the trends were no longer significant. CONCLUSION: Intake of very long-chain n-3 fatty acids as reflected in adipose tissue content is inversely associated with risk of myocardial infarction. Trans fatty acids, linoleic and alpha-linolenic acid were intercorrelated and associated with increased risk. It is suggested that the increased risk may be connected to trans fatty acids or to some other factor associated with margarine consumption. European Journal of Clinical Nutrition 54, 618-625.

Whole blood folate, homocysteine in serum, and risk of first acute myocardial infarction.

High level of total homocysteine (tHcy) is a risk factor for coronary artery disease (CAD), but the mechanism is not known. The serum concentration of tHcy, total cholesterol, high density lipoprotein cholesterol (HDL-C), and apolipoprotein A-I (apo A-I) and the concentration of folate in whole blood were measured in 107 patients with first acute myocardial infarction (MI) and 103 controls. The level of whole blood folate was lower and that of tHcy higher in cases than in controls. An increase of 50 nmol/l whole blood folate was associated with an OR for MI of 0.75, and an increase of 5 micromol/l tHcy with an OR for MI of 1.57. Correlations were observed between the levels of whole blood folate and tHcy and between whole blood folate and alcohol intake, and in MI cases, between tHcy, HDL-C, and apo A-I as well as between HDL-C and alcohol intake. The number of cigarette smokers was higher among cases than controls. In smokers, the level of tHcy was higher and that of whole blood folate lower than in non-smokers. After adjustment for smoking, the whole blood folate and tHcy-associated risks of MI became non-significant. We conclude that smoking may affect folate status and tHcy level adversely. The risk of MI in smokers may at least partly be attributed to hyperhomocysteinemia or low folate.

[Cardiovascular risk factors in Oslo, Sogn and Fjordane and Finnmark. Study of 40-year old subjects in Oslo 1981-88]. / Risikofaktorer for hjerte- og karsykdom i Oslo, Sogn og Fjordane og Finnmark. 40-åringsundersøkelsen i Oslo 1981-88.

Cardiovascular risk factor levels among 40-year olds in Oslo were studied from the early 1970s until the late 1980s. Comparison has been made with similar data for the same period from two other regions in the country. The serum cholesterol level in men decreased from 6.3 mmol/l in 1972-73 to 5.9 mmol/l in 1985-88 and the proportion of men who smoked on a daily basis decreased from 51.8% to 40.8%. The proportion of female smokers increased from 37.4% in 1981-84 to 39.5% in 1985-88. There was a decrease in systolic blood pressure among men from 1972-73 to 1985-88. From 1981-84 to 1985-88 there was a minor increase for both sexes in the proportion of physically inactive for both sexes or those with a body mass index > 30. Prior to 1980 cardiovascular risk factors were most favourable in Sogn og Fjordane, and least favourable in Finnmark, with men from Oslo positioned somewhere in between these counties. With the exception of women's smoking habits and, for both sexes, the degree of physical activity, people living in Oslo in 1985-88 had a more favourable risk factor status than those in Sogn og Fjordane in 1985 and in Finnmark in 1987. Despite a degree of uncertainty because of methodological issues, the results indicate a reduction in risk factors of cardiovascular disease among men in Oslo during the 15 years covered by the study.

[Regional differences in risk factors in Oslo. Smoking, exercise, body mass index, blood lipids and blood pressure in 40-year old subjects 1985-88]. / Regionale ulikheter i sykdomsrisiko i Oslo. Røyke- og mosjonsvaner, kroppsmasseindeks, blodlipidnivå og blodtrykk blant 40-åringer 1985-88.

The general mortality rate in Oslo (capital city of Norway) is high compared with the rest of the country, and varies considerably from area to area within the city. This study highlights the differences in cardiovascular risk factors among 40 year-olds in different areas of Oslo between 1985 and 88. A total of 14,220 persons were included in the study. The city was divided into four geographical areas with distinct differences in socio-economic conditions. For both sexes all risk factors were shown to be more favourable in the more affluent areas than in the poorer area of the inner city. Also for both sexes the proportion of persons who smoked on a daily basis varied from 29% in the "best" area to 49% in the "worst" area of the city. The differences in serum cholesterol in the different areas were less pronounced than for the other risk factors. The greatest differences in risk factors were observed among women. The proportion of physically inactive women was 27% in the poorer area compared with 17% in the more affluent part of the city, and the body mass index was above 30 for 8.8% and 2.8% of women respectively. Similarly, the proportion of women with serum cholesterol > 7 mmol/l, triglycerides > or = 2.5 mmol/l, systolic blood pressure > or = 140 mm or diastolic blood pressure > or = 90 mm was almost twice as high for those living in poor socioeconomic conditions than those who were in a better position.

Serum lipids in postmenopausal or perimenopausal women using estrogen alone, estrogen with levonorgestrel, or estrogen with norethisterone, compared with nonusers: results from a cross-sectional study in two Norwegian counties 1985-1988.

The aim of this study was to compare, in a population setting of postmenopausal or perimenopausal women aged 40 to 54, the levels of serum lipids in women using different hormone replacement therapy (HRT) regimens with women using no sex hormones. There was no unequivocal tendency of a more healthy lifestyle among those using HRT than among nonusers. Any type of regimen was associated with a lower mean level of total and calculated low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol was 0.08 mmol/L (5.2%) higher in those using estrogen alone, 0.07 mmol/L (4.5%) higher in users of HRT with norethisterone, and 0.07 mmol/L (4.5%) lower in users of HRT with levonorgestrel, compared with nonusers. The ratio of total-to-HDL cholesterol was lower by 0.37 (6.1%) in those using estrogen alone, by 0.65 (12.3%) in those using HRT with norethisterone, and by 0.24 (5.3%) in those using estrogen with levonorgestrel. There was no association between body mass index and HDL-cholesterol among women who used HRT with norethisterone, whereas an inverse relationship was present in those using estrogen alone and in nonusers (P [interaction] < 0.05).

Coffee consumption and plasma total homocysteine: The Hordaland Homocysteine Study.

The health consequences of coffee drinking remain controversial. We report on an association between coffee consumption and the concentration of total homocysteine (tHcy) in plasma, a risk factor for cardiovascular disease and for adverse pregnancy outcome. The study population consisted of 7589 men and 8585 women 40-67 y of age and with no history of hypertension, diabetes, ischemic heart disease, or cerebrovascular disease. They were recruited from Hordaland county of western Norway in 1992-1993. Daily use of coffee was reported by 89.1% of the participants, of whom 94.9% used caffeinated filtered coffee. There was a marked positive dose-response relation between coffee consumption and plasma tHcy, which was stronger than the relation between coffee and total serum cholesterol. In 40-42-y-old men, mean tHcy was 10.1 mumol/L for nonusers and 12.0 mumol/L for drinkers of > or = 9 cups of coffee/d. Corresponding tHcy concentrations in 40-42-y-old women were 8.2 and 10.5 mumol/L, respectively. Although coffee drinking was associated with smoking and lower intake of vitamin supplements and fruit and vegetables, the coffee-tHcy association was only moderately reduced after these variables were adjusted for. The combination of cigarette smoking and high coffee intake was associated with particularly high tHcy concentrations. A strong inverse relation between tea and tHcy concentration in univariate analysis was substantially attenuated after smoking and coffee drinking were adjusted for. The results of the present report should promote future studies on tHcy as a possible mediator of adverse clinical effects related to heavy coffee consumption.

Cardiovascular risk factors in Norwegian women using oral contraceptives: results from a cardiovascular health screening 1985-88.

We analyzed data from 4,905 women aged 20-39 and 14,803 aged 40-49 who attended a health survey in Norway 1985-88, to study cardiovascular risk factors in users of oral contraceptives, all types and specifically by formulation. In age group 20-39, users of low-dose estrogen/ progestin regimens were younger, had lower body mass index (BMI), less often reported coronary heart disease in relatives, and less often used saturated fat on bread than did non-users. In age group 40-49, smoking was more prevalent in users of low-dose estrogen/progestin than in non-users. In both age groups the mean ratio of total/HDL cholesterol, the mean level of non-fasting triglycerides, and the mean systolic and diastolic blood pressures were higher in oral contraceptive users than in non-users. Among the users, a more favorable pattern was found in women using progestin-only oral contraceptives, as blood pressure levels were equal to those of non-users and total cholesterol and triglycerides were both 0.1-0.2 mmol/l below the non-users, in both age groups. However, users of low-dose estrogen formulations containing desogestrel 0.15 mg, norethisterone (norethindrone) 0.5 mg or lynestrenol 2.5 mg had the highest levels of HDL, even higher than the non-users. A pattern of higher triglycerides and higher ratio of total/ HDL cholesterol was found in smokers, compared with non-smokers, among users of any type of contraceptives, and in non-users.

Total plasma homocysteine and cardiovascular risk profile. The Hordaland Homocysteine Study.

OBJECTIVE: To estimate the relations between established cardiovascular risk factors and total homocysteine (tHcy) in plasma. DESIGN: Health examination survey by the Norwegian Health Screening Service in 1992 and 1993. SETTING: General community, Hordaland County of Western Norway. PARTICIPANTS: A total of 7591 men and 8585 women, 40 to 67 years of age, with no history of hypertension, diabetes, coronary heart disease, or cerebrovascular disease were included. MAIN OUTCOME MEASURE: Plasma tHcy level. RESULTS: The level of plasma tHcy was higher in men than in women and increased with age. In subjects 40 to 42 years old, geometric means were 10.8 mumol/L for 5918 men and 9.1 mumol/L for 6348 women. At age 65 to 67 years, the corresponding tHcy values were 12.3 mumol/L (1386 men) and 11.0 mumol/L (1932 women). Plasma tHcy level increased markedly with the daily number of cigarettes smoked in all age groups. Its relation to smoking was particularly strong in women. The combined effect of age, sex, and smoking was striking. Heavy-smoking men aged 65 to 67 years had a mean tHcy level 4.8 mumol/L higher than never-smoking women aged 40 to 42 years. Plasma tHcy level also was positively related to total cholesterol level, blood pressure, and heart rate and inversely related to physical activity. The relations were not substantially changed by multivariate adjustment, including intake of vitamin supplements, fruits, and vegetables. CONCLUSIONS: Elevated plasma tHcy level was associated with major components of the cardiovascular risk profile, ie, male sex, old age, smoking, high blood pressure, elevated cholesterol level, and lack of exercise. These findings should influence future studies on the etiology and pathogenesis of cardiovascular disease.

The relationship of coffee consumption to various self-reported cardiovascular events in middle-aged Norwegian men and women.

The association between number of cups of coffee consumed per day and self-reported heart infarction, angina pectoris, or symptoms of angina pectoris was studied in 11635 men and 11785 women, aged 40-54 years, who attended two cardiovascular screenings. Questionnaire information on heart infarction has previously been found to be reliable. Altogether 240, 201 and 241 men reported heart infarction, angina pectoris (without heart infarction) and symptoms of angina pectoris, respectively, at the last, but not at the first screening. The corresponding figures for women were 35, 102 and 395. Univariate analysis showed a positive association between number of cups of coffee and self-reported heart infarction. The same applies to self-reported angina pectoris. After adjustment for major coronary risk factors, the associations became weaker. The relative risks of self-reported heart infarction between users of nine or more cups and users of less than one cup were 1.7 (95% CI: 1.0, 3.0) and 1.5 (0.3, 7.5) in men and women, respectively. The relative risks were smaller than those found in a previous study relating coffee consumption to coronary heart disease mortality. For self-reported angina pectoris the corresponding relative risks were 1.4 (0.8, 2.7) for men and 2.7 (1.1, 6.7) for women. The study is suggestive of a modest relationship between coffee consumption and self-reported occurrence of both heart infarction and angina pectoris.

Coffee and cancer: a prospective study of 43,000 Norwegian men and women.

Relationships between coffee drinking and cancer incidence were examined in a 10-year complete follow-up of 21,735 men and 21,238 women aged 35-54 years. The study population participated in a cardiovascular screening in three countries in Norway during 1977-82. Data on coffee and smoking habits were based on information from a self-administered questionnaire. There was no association between coffee consumption and overall risk of cancer. A positive association was found between coffee drinking and risk of lung cancer, also after adjustment for age, cigarette smoking, and county of residence. Residual confounding by cigarette smoking and other lifestyle factors cannot be ruled out. A negative association was found with cancer of buccal cavity and pharynx and with malignant melanoma in women. No significant associations were found between coffee drinking and incidence of cancer of the pancreas or the bladder.

Assessment of coronary heart disease risk, I. A postal inquiry among primary care physicians.

The purpose of the present study was to examine general practitioners' abilities to make a correct estimation of the risk of coronary heart disease (CHD). A 10% random sample of Norwegian primary care physicians (n = 288) received a questionnaire that presented 10 case histories containing information about five CHD risk factors. The respondents' risk estimation was compared with a composite score computed from epidemiologic data. The observed general tendency was towards underestimating the CHD risk. However, 'high-risk' histories were recognized as CHD risk persons. Assessment of CHD risk due to multiple marginal abnormalities was only exceptionally correct. Hypercholesterolaemia and hypertension in men were acknowledged as contributing to clinically significant CHD risk only by a minority of GPs. Heavy smoking and a positive family history were associated with a more accurate estimation of CHD risk. Forty per cent of the physicians did not recognize the sex dependency of cholesterol as a CHD risk factor. None of the physician characteristics could predict variation in correct risk assessment.

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.

Mortality in relation to smoking history: 13 years' follow-up of 68,000 Norwegian men and women 35-49 years.

A total of 44,290 men and 24,535 women aged 35-49 have been followed with respect to different causes of death during 13.3 years on average. A detailed history of smoking, together with other important risk factors, were recorded in a standardized way. Compared with the classical American and British studies, the excess mortality for the smokers was largely the same for the majority of causes. The exceptions were cerebrovascular mortality and suicides and accidents, which were more strongly related to smoking in this study. Furthermore, men who smoked only pipe, had nearly the same coronary heart disease mortality as men who smoked only cigarettes. The same applies to lung cancer mortality. Among men who had quit cigarette smoking, the coronary heart disease mortality decreased with time since quitting to almost the level of the never cigarette smokers after 5 years or more.

Norwegian case-control study testing the hypothesis that seafood increases the risk of thyroid cancer.

The hypothesis that consumption of seafood increases the risk of thyroid cancer has been tested by means of a matched case-control study. Linking the file of the National Health Screening Service (NHSS) containing dietary information about 60,000 Norwegians with the 1955-89 thyroid-cancer file of the Cancer Registry, by means of the 11-digit person-number, resulted in 92 cases--each of whom was matched with five controls with regard to age, gender, and place of residence. Forty-eight cases had answered questions on diet before diagnosis; 44 did so after diagnosis. Exposure data on seafood and seafood-related vitamins were recovered from the NHSS files for all 552 subjects. Odds ratios (OR) were computed by means of conditional logistic regression analysis. Univariate analysis of the 48 sets in which the case had answered the dietary questionnaire prior to the thyroid cancer diagnosis, as well as of all 92 sets, indicate that regular users of cod-liver oil, fish liver, or fish sandwich-spread run a higher risk of thyroid cancer than irregular and nonusers, and people eating more fish dinners per week also run a higher risk of thyroid cancer. Stepwise regression analysis corroborates the study hypothesis by showing that these two seafood variables increase the risk of thyroid cancer significantly. On the other hand, the results of a simultaneous regression analysis of these two seafood variables and a dietary vitamin-D index-variable tend to reduce the tenability of the above-mentioned conclusion since none of the OR estimates (all greater than one) reached significance in this part of the statistical analysis.

Milk--a better drink? Relationships with total serum cholesterol in a cross-sectional survey. The Nordland Health Study.

Cross-sectional studies have not consistently shown a positive association between milk drinking and serum cholesterol. We studied this relationship in a cohort of 7506 men and women aged 40-42 years in the county of Nordland in northern Norway (72% of all subjects in the age-bracket living in the county). We found a positive relationship between the percentage of fat in the milk and total serum cholesterol, but no positive relationship between whole fat milk consumption (number of glasses per day) and serum cholesterol. The findings were, however, to some extent influenced by effects of present atherosclerotic disease, or perceived threat of this.