Heterogeneity in cost-effectiveness of lifestyle counseling for metabolic syndrome risk groups -primary care patients in Sweden.

BACKGROUND: Clinical trials have indicated that lifestyle interventions for patients with lifestyle-related cardiovascular and diabetes risk factors (the metabolic syndrome) are cost-effective. However, patient characteristics in primary care practice vary considerably, i.e. they exhibit heterogeneity in risk factors. The cost-effectiveness of lifestyle interventions is likely to differ over heterogeneous patient groups. METHODS: Patients (62 men, 80 women) in the Kalmar Metabolic Syndrome Program (KMSP) in primary care (Kalmar regional healthcare area, Sweden) were divided into three groups reflecting different profiles of metabolic risk factors (low, middle and high risk) and gender. A Markov model was used to predict future cardiovascular disease and diabetes, including complications (until age 85 years or death), with health effects measured as QALYs and costs from a societal perspective in Euro (EUR) 2012, discounted 3%. Simulations with risk factor levels at start and at 12 months follow-up were performed for each group, with an assumed 4-year sustainability of intervention effects. RESULTS: The program was estimated cost-saving for middle and high risk men, while the incremental cost vs. do-nothing varied between EUR 3,500 - 18,000 per QALY for other groups. There is heterogeneity in the cost-effectiveness over the risk groups but this does not affect the overall conclusion on the cost-effectiveness of the KMSP. Even the highest ICER (for high risk women) is considered moderately cost-effective in Sweden. The base case result was not sensitive to alternative data and methodology but considerably affected by sustainability assumptions. Alternative risk stratifications did not change the overall conclusion that KMSP is cost-effective. However, simple grouping with average risk factor levels over gender groups overestimate the cost-effectiveness. CONCLUSIONS: Lifestyle counseling to prevent metabolic diseases is cost-effective in Swedish standard primary care settings. The use of risk stratification in the cost-effectiveness analysis established that the program was cost-effective for all patient groups, even for those with very high levels of lifestyle-related risk factors for the metabolic syndrome diseases. Heterogeneity in the cost-effectiveness of lifestyle interventions in primary care patients is expected, and should be considered in health policy decisions.

Risk of malignancies in relation to terrestrial gamma radiation in a Swedish population cohort.

Results of epidemiological studies on terrestrial gamma radiation (TGR) and related malignancies have not been consistent. This study is a thorough examination of this relationship. Records on all individuals living in two Swedish counties in 1973, along with their annual dwelling coordinates during the 28-year follow-up period, were retrieved from the National Archives and Statistics Sweden. We used Geographical Information System (GIS) to match the individuals' dwelling coordinates annually to the TGR given in 200×200 m grids produced by the Geological Survey of Sweden. Cases of malignancies and deaths were retrieved from the Swedish Cancer Register. During the follow-up period 61,503 incident cases were included in the analyses and in total 11 million person-years were recorded. Cox regression was used both in a linear continuous model and analyses of six exposure categories. Adjustments were made for sex, age, and population density. The hazard ratio (HR) per 100 nanoGray/hour (nGy/h) was significantly increased for total malignancies and for several sites; however, contrary to expectations, an obvious and anticipated linear exposure-response relationship could not be identified. With the lowest exposure category (0-60 nGy/h) as reference, a statistically significantly increased HR for total malignancies was seen in all exposure categories, except in the highest category 96-366 nGy/h. For breast cancer, thyroid cancer and leukaemia an obvious exposure-response could not be seen.

Bone mineral density changes in relation to environmental PCB exposure.

BACKGROUND: Bone toxicity has been linked to organochlorine exposure following a few notable poisoning incidents, but epidemiologic studies in populations with environmental organochlorine exposure have yielded inconsistent results. OBJECTIVES: The aim of this study was to investigate whether organochlorine exposure was associated with bone mineral density (BMD) in a population 60-81 years of age (154 males, 167 females) living near the Baltic coast, close to a river contaminated by polychlorinated biphenyls (PCBs). METHODS: We measured forearm BMD in participants using dual energy X-ray absorptiometry; and we assessed low BMD using age- and sex-standardized Z-scores. We analyzed blood samples for five dioxin-like PCBs, the three most abundant non-dioxin-like PCBs, and p,p'-dichloro-phenyldichloroethylene (p,p'-DDE). RESULTS: In males, dioxin-like chlorobiphenyl (CB)-118 was negatively associated with BMD; the odds ratio for low BMD (Z-score less than -1) was 1.06 (95% confidence interval, 1.01-1.12) per 10 pg/mL CB-118. The sum of the three most abundant non-dioxin-like PCBs was positively associated with BMD, but not with a decreased risk of low BMD. In females, CB-118 was positively associated with BMD, but this congener did not influence the risk of low BMD in women. CONCLUSIONS: Environmental organochlorine exposures experienced by this population sample since the 1930s in Sweden may have been sufficient to result in sex-specific changes in BMD.

Cadmium exposure pathways in a population living near a battery plant.

OBJECTIVES: The objectives of the present study were to assess the relative impact of different pathways of environmental cadmium (Cd) exposure and to evaluate the contribution from locally produced vegetables and root crops to the total dietary intake of Cd. METHODS: Cadmium in urine was determined for 492 individuals living near a closed down battery factory in Sweden. For each individual we created an environmental exposure-index based on Cd emissions to ambient air and number of years living at various distances from the plant. This information as well as dietary data were collected via questionnaires. Samples of soil, carrots and/or potatoes were collected from 37 gardens and analysed for Cd concentration. RESULTS: Eating home grown vegetables/potatoes, environmental Cd-exposure-index, female gender, age above 30 years and smoking more than one pack of cigarettes daily for at least 10 years were found to be significantly associated with increased urine concentrations of Cd (UCd>1.0 nmol/mmol creatinine). We found a statistically significant relation between Cd in urine and environmental Cd-exposure-index in persons eating home grown vegetables/potatoes regularly. Cd concentrations in home grown carrots, potatoes and in garden soil were highest in the area closest to the factory. Daily consumption of potatoes and vegetables cultivated in the vicinity of the closed battery factory was estimated to increase Cd intake by 18-38%. CONCLUSION: The present study shows that consumption of locally grown vegetables and root crops was an important exposure pathway, in subjects living near a nickel-cadmium battery plant, whereas direct exposure via ambient air was less important.

Cadmium exposure and distal forearm fractures.

UNLABELLED: The aim of this study was to analyze the relationship between low-level cadmium exposure and distal forearm fractures. Altogether, 1021 men and women exposed to cadmium in Sweden were included. The study indicates that cadmium exposure is associated with increased risk of forearm fractures in people over the age of 50. INTRODUCTION: Very few studies have been performed on environmental risk factors for fractures. Cadmium is known to cause damage to the kidneys and in high doses to the bone. The aim of this study was to analyze the relationship between low-level cadmium exposure and distal forearm fractures. MATERIALS AND METHODS: A total of 479 men and 542 women, 16-81 years of age, that were environmentally or occupationally exposed to cadmium were examined in 1997. Cadmium in urine was used to estimate dose, and information about previous fractures and risk factors for fractures was obtained from questionnaires. Fractures were validated using medical records. The association between cadmium dose and risk of forearm fracture was evaluated using Cox proportional hazard regression analysis. RESULTS AND CONCLUSION: The mean urinary cadmium in the study population was 0.74 nmol cadmium/mmol creatinine (10% and 90% percentiles are 0.19 and 1.42, respectively). For fractures occurring after the age of 50 years (n = 558, 32 forearm fractures), the fracture hazard ratio, adjusted for gender and other relevant co-variates, increased by 18% (95% CI, 1.0-38%) per unit urinary cadmium (nmol cadmium/mmol creatinine). When subjects were grouped in exposure categories, the hazard ratio reached 3.5 (90% CI, 1.1, 11) in the group of subjects with urinary cadmium between 2 and 4 nmol/mmol creatinine and 8.8 (90% CI, 2.6, 30) in the group of subjects with > or = 4 nmol/mmol creatinine. Associations between cadmium and fracture risk were absent before the age of 50. Cadmium exposure is associated with increased risk of forearm fractures in people over 50 years of age.

Using environmental concentrations of cadmium and lead to assess human exposure and dose.

OBJECTIVES: Using environmental concentrations and Geographic Information Systems (GIS) to model human exposure is an emerging tool in environmental epidemiology. To evaluate the usefulness of this, we investigated to what extent cadmium and lead concentrations in soil and moss could be used as potential determinants for cadmium and lead exposure for a population living near a battery plant. METHODS: Cadmium in urine and blood and lead in blood, as well as food, smoking habits, places of residence, occupations and health, were determined for 512 individuals living near a closed down battery factory in Sweden. Cadmium and lead contents in moss were available through previous assessments by the Geological Survey of Sweden. Soil samples had been collected at various distances from the factory, and analyzed for cadmium and lead contents in 1990. Kriging technique in GIS was used to create areas with different metal concentrations based on these measurements. By linking individual address coordinates to mapped concentration levels, each study subject home address received a value of cadmium and lead in moss and soil. RESULTS: We found a statistically significant association between lead in soil and lead in blood, for female subjects eating homegrown vegetables regularly. No significant association was found between cadmium in soil and cadmium in urine for either gender in the study population. No clear associations were found for either gender regarding lead and cadmium in moss and lead in blood or cadmium in urine or in blood. CONCLUSION: In general, environmental concentrations may not be useful surrogates for assessing human exposure to lead and cadmium, but concentrations of metals in soil around emitting point sources can be a complement for estimating the exposure in certain subgroups.