Bjarne K. Jacobsen

Does high soy milk intake reduce prostate cancer incidence? The Adventist Health Study (United States)

Objectives: Recent experimental studies have suggested that isoflavones (such as genistein and daidzein) found in some soy products may reduce the risk of cancer. The purpose of this study was to evaluate the relationship between soy milk, a beverage containing isoflavones, and prostate cancer incidence.Methods: A prospective study with 225 incident cases of prostate cancer in 12,395 California Seventh-Day Adventist men who in 1976 stated how often they drank soy milk.Results: Frequent consumption (more than once a day) of soy milk was associated with 70 per cent reduction of the risk of prostate cancer (relative risk=0.3, 95 percent confidence interval 0.1-1.0, p-value for linear trend=0.03). The association was upheld when extensive adjustments were performed.Conclusions: Our study suggests that men with high consumption of soy milk are at reduced risk of prostate cancer. Possible associations between soy bean products, isoflavones and prostate cancer risk should be further investigated.

Cohort profile: The Tromsø Study

The Tromso Study was initiated in 1974 in an attempt to help combat the high mortality of cardiovascular diseases in Norway, that was particularly pronounced among middle-aged men. In the mid-1970s, Norwegian men had a 20% risk of dying of myocardial infarction (MI) before the age of 75 years. The situation in Northern Norway was even worse. The primary aim of the Tromso Study was to determine causes of the high cardiovascular mortality, and also to develop ways of preventing heart attacks and strokes. This was reflected through the first name of the study: The Tromso Heart Study. However, during the 37 years since the first examination of the Tromso Study took place, increasing emphasis has been put on other chronic diseases and conditions, in particular atrial fibrillation, venous thromboembolism, diabetes mellitus, osteoporosis and fractures. It has been a deliberate policy to invite a wide range of faculty research groups to join in with subprojects in the surveys, and there are currently some 100 different ongoing research projects based on the data from the consecutive six surveys. The study was initially funded by the University of Tromso, and has been so for the entire period since 1974, but there have also been substantial contributions, directly and indirectly from, for example, the National Screening Services, the Research Council of Norway, Northern Norway Regional Health Authority, Norwegian Council on Cardiovascular Diseases and Norwegian Foundation for Health and Rehabilitation. Teams of investigators approach public research programmes for funding of the different examinations conducted. Tromso is the largest city in Northern Norway. It is situated 400 km north of the Arctic Circle, and has approximately 67 000 inhabitants. The physical living conditions are dominated by dramatic changes in the light with 2 months of midnight sun and 2 months of the polar night. However, due to the Gulf Stream, the climate is relatively mild, the latitude (698N) taken into account.

Risk Factors for Abdominal Aortic Aneurysms A 7-Year Prospective Study: The Tromsø Study, 1994–2001

Background— Abdominal aortic aneurysm is an asymptomatic condition with a high mortality rate related to rupture. Methods and Results— In a cohort of 2035 men and 2310 women in Tromsø, Norway, who were 25 to 82 years old in 1994, the authors identified risk factors for incident abdominal aortic aneurysm over the next 7 years. The impact of smoking was studied in particular. Ultrasound examination was performed initially in 1994/1995 and repeated in 2001. There were 119 incident cases of abdominal aortic aneurysms (an incidence of 0.4% per year). Male sex and increasing age were strong risk factors. In addition, the following variables were significantly associated with increased abdominal aortic aneurysm incidence: Smoking (OR=13.72, 95% CI 6.12 to 30.78, comparing current smokers of ≥20 cigarettes/d with never-smokers), hypertension (OR=1.54, 95% CI 1.03 to 2.30), hypercholesterolemia (OR=2.11, 95% CI 1.23 to 3.64, comparing subjects with serum total cholesterol ≥7.55 mmol/L with those with total cholesterol <5.85 mmol/L), and low high-density lipoprotein cholesterol (OR=3.25, 95% CI 1.68 to 6.27, comparing subjects with high-density lipoprotein cholesterol <1.25 mmol/L with those with high-density lipoprotein ≥1.83 mmol/L). In addition, use of statins was associated with increased risk of abdominal aortic aneurysm (OR=3.77, 95% CI 1.45 to 9.81), but this was probably a marker of high risk of cardiovascular diseases. Conclusions— The results demonstrate strong associations between traditional atherosclerosis risk factors and the risk of incident abdominal aortic aneurysms.

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 counties 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.

Use of alcohol, tobacco and coffee, and risk of pancreatic cancer.

Associations between pancreatic cancer and use of alcohol, tobacco and coffee were examined in a Norwegian prospective study of 16,713 individuals in which 63 cases occurred. The associations were assessed using techniques for stratified logistic regression. Of the potential risk factors considered, use of alcohol showed the strongest positive association, with an estimated relative risk of 5.4 for those with a frequent use as compared with non-drinkers (P less than 0.001). A clear positive association was also obtained with chewing of tobacco or use of snuff. For cigarette smoking a somewhat weaker association was observed. No association could be established for pipe smoking or coffee drinking. In general, more clear-cut results were found when analysis was restricted to histologically-verified cases.

Walking after stroke: Does it matter? Changes in Bone mineral density within the first 12 months after stroke. A longitudinal study

Abstract: Stroke patients have increased risk of hip fractures. Nearly all fractures occur on the hemiplegic side, and reduced bone mineral density (BMD) may be an important predisposing factor. The aim of this study was to investigate the degree of demineralization within the first year after stroke, and to elucidate a possible difference in patients with high versus low ambulatory levels. Forty acute stroke patients were followed (17 initially wheelchair-bound and 23 initially ambulatory). BMD was measured in the proximal femur bilaterally at a mean 6 days, 7 months and 1 year after stroke onset using dual-energy X-ray absorptiometry. Ambulatory status was independently associated with changes in BMD (p≤0.005) 1 year after stroke. The 17 initially wheelchair-bound patients had a significant 10% reduction in BMD at the paretic side and 5% reduction at the non-paretic side (p<0.001), while the 23 patients initially able to walk had a significant loss (3%) only at the paretic side (p = 0.01). The analysis also indicated that the major reduction in BMD took place within the first 7 months. Two months after stroke 12 of the wheelchair-bound patients had relearned to walk. At the paretic side the 1 year changes in BMD in the patients who stayed wheelchair-bound, the patients who relearned to walk within the first 2 months and the patients who were able to walk throughout the study were 13%, 8% and 3%, respectively, and a statistically significant trend with ambulatory level was found (p = 0.007). This study provides clear evidence that lack of mobility and weight-bearing early after stroke is an important factor for the greater bone loss in the paretic leg, but that relearning to walk within the first 2 months after stroke, even with the support of another person, may reduce the bone loss after immobilization.

Changes in muscle mass, fat mass, and bone mineral content in the legs after stroke: a 1 year prospective study

Demineralization and muscle atrophy, common among patients with hemiplegia, may be risk factors for future hip fracture. The aim of this longitudinal study was to investigate changes in lean (muscle) mass and bone mineral content (BMC) of the legs during the first year after stroke according to the patients ambulatory level. Twenty-five patients immobilized due to acute stroke were followed. BMC and lean mass of each leg were measured at a mean of 7 days, 2 months, 7 months, and 1 year after the stroke using dual-energy X-ray absorptiometry. Both BMC and lean mass had decreased significantly in the paretic leg (p < 0.05) at the 1 year evaluation and the loss was significantly greater on the paretic side compared with the nonparetic side (p < 0.001). Patients who had not relearned to walk at the 2 month evaluation (n = 12) lost 6% (p < 0.05) of their lean mass in the paretic leg during this time period, and this mass was not regained within the subsequent 10 months. In contrast, a significant 5% loss of lean mass found at 2 months on the nonparetic side was regained completely. With respect to the patients who relearned to walk within the first 2 months (n = 13) lean mass had increased by 5% after 1 year (p < 0.05) in the nonparetic leg, whereas no significant changes were found in the paretic leg during follow-up. Both groups of patients did, however, lose bone mineral in the paretic leg during the first year after stroke (9% and 6%, respectively, p < 0.05), but only the patients who were still unable to walk by 2 months had significant bone loss in the nonparetic leg also (3%, p < 0.05). Thus, lean muscle mass is rapidly lost and may be regained shortly after stroke, whereas loss of BMC appears difficult to prevent, especially on the paretic side. Regaining muscle mass may, however, slow the loss of bone mineral.

Bone Mineral Density in Acute Stroke Patients Low Bone Mineral Density May Predict First Stroke in Women

Background and Purpose— Osteoporosis and stroke share several risk factors, including age, smoking, low physical activity, and hypertension. Thus, low bone mineral density (BMD) and high stroke risk may be related. We examined the relationship between BMD and acute stroke in noninstitutionalized men and women aged ≥60 years. Methods— Sixty-three stroke patients (33 women and 30 men) and 188 control subjects from the general population were included. BMD was measured by using dual-energy x-ray absorptiometry at both proximal femurs. The measurements of the stroke patients were performed 6 days after the onset of stroke. Results— The BMD at the femoral neck in the female stroke patients was 8% lower than in the control subjects (P =0.007). In men, no difference in BMD between the stroke patients and their controls was found. Women with BMD values in the lowest quartile had a higher risk of stroke than women with BMD values in the highest quartile (OR 4.8), and the probability value for linear trend over the quartiles was statistically significant (P =0.003). The OR for stroke increased 1.9 per SD (0.13 g/cm2) reduction in BMD, and the association between low BMD and stroke in women remained significant when the analysis was adjusted for potential confounders. Conclusions— Female, but not male, stroke patients have lower BMD than population controls. Low BMD may predict stroke in women.

Ambulatory level and asymmetrical weight bearing after stroke affects bone loss in the upper and lower part of the femoral neck differently: bone adaptation after decreased mechanical loading

The aim of this 1-year prospective study of acute stroke patients was to determine the effects of walking and asymmetrical weight bearing on the loss of bone mineral in the upper and lower femoral neck. Forty patients were followed. Eight remained unable to walk, whereas 32 relearned to walk independently within 7 months (12 shortly after the stroke, 15 by 2 months, 5 by 7 months). Bone mineral density (BMD) was measured in the proximal femur within the first week after stroke and 1 year later; regional BMD changes were computed for the lower and upper femoral neck. The lower part of the femoral neck is mainly influenced by compressive stresses of the hip, the upper part by tensile stresses during walking. When comparing mean BMD loss in groups of patients according to when they relearned to walk, a statistically significant trend in BMD loss was found in the lower femoral neck on both the paretic and nonparetic sides (p < 0.01 and p = 0.01, respectively), whereas, for the upper femoral neck, no significant trend was seen (p >/= 0.1). In addition, the body weight distribution during standing was assessed by use of a force-plate in 38 patients who could stand independently at the 7 month evaluation. The only significant correlation between changes in BMD and asymmetrical weight bearing was found in the lower femoral neck on the paretic side (r = 0.6, p < 0.001). In conclusion, this study shows that the reduction in BMD in the femoral neck occurs mainly in the lower part of the neck and on the paretic side. The BMD loss depended on when or if the patients relearned to walk, but also on the amount of body weight born on the paretic leg. Thus, measuring the lower part of the femoral neck gives a better estimate of the impact of gait and weight bearing than measuring the total femoral neck.

Total Mortality is Increased in Rheumatoid Arthritis. A 17-Year Prospective Study

Abstract: The purpose of this study was to determine the total and cause-specific mortality in rheumatoid arthritis (RA) patients compared to a control population in northern Norway. One hundred and eighty-seven patients with RA and 930 population controls matched for age, gender and municipality were followed until death or for a maximum of 17 years. The total mortality in RA patients was twice that of their controls (MRR = 2.0, 95% CI = 1.6-2.5). Patients possessing serum rheumatoid factors did not have a higher relative mortality than the seronegative patients. There was no statistically significant increased mortality from cancer or cardiovascular diseases. Indications for a higher death rate in RA patients than in controls were found for infection and sudden death.