Original article: Meta‐analysis of potassium intake and the risk of stroke

Vinceti M, Filippini T, Crippa A, de Sesmaisons A, Wise LA, Orsini N

J Am Heart Assoc. 2016;5:e004210

Abstract

Background: The possibility that lifestyle factors such as diet, specifically potassium intake, may modify the risk of stroke has been suggested by several observational cohort studies, including some recent reports. We performed a systematic review and meta‐analysis of existing studies and assessed the dose–response relation between potassium intake and stroke risk.

Methods and Results: We reviewed the observational cohort studies addressing the relation between potassium intake, and incidence or mortality of total stroke or stroke subtypes published through August 6, 2016. We carried out a meta‐analysis of 16 cohort studies based on the relative risk (RR) of stroke comparing the highest versus lowest intake categories. We also plotted a pooled dose–response curve of RR of stroke according to potassium intake. Analyses were performed with and without adjustment for blood pressure. Relative to the lowest category of potassium intake, the highest category of potassium intake was associated with a 13% reduced risk of stroke (RR=0.87, 95% CI 0.80–0.94) in the blood pressure–adjusted analysis. Summary RRs tended to decrease when original estimates were unadjusted for blood pressure. Analysis for stroke subtypes yielded comparable results. In the spline analysis, the pooled RR was lowest at 90 mmol of potassium daily intake (RRs=0.78, 95% CI 0.70–0.86) in blood pressure–adjusted analysis, and 0.67 (95% CI 0.57–0.78) in unadjusted analysis.

Conclusions: Overall, this dose–response meta‐analysis confirms the inverse association between potassium intake and stroke risk, with potassium intake of 90 mmol (≈3500 mg)/day associated with the lowest risk of stroke.

     pdfScarica pdf

Original article: Determinants of serum cadmium levels in a Northern Italy community: A cross-sectional study

Filippini T, Michalke B, Malagoli C, Grill P, Bottecchi I, Malavolti M, Vescovi L, Sieri S, Krogh V, Cherubini A, Maffeis G, Modenesi M, Castiglia P, Vinceti M.

Environ Res. 2016 Oct;150:219-226

Abstract

INTRODUCTION: Cadmium (Cd) is a heavy metal and a serious environmental hazard to humans. Some uncertainties still exist about major sources of Cd exposure in non-occupationally exposed subjects in addition to cigarette smoking, such as diet and outdoor air pollution. We sought to determine the influence of these sources on a biomarker of exposure, serum Cd concentration. METHODS: We recruited 51 randomly selected residents from an Italian urban community, from whom we obtained detailed information about dietary habits and smoking habits, and a blood sample for serum Cd determination. We also assessed outdoor air Cd exposure, by modeling outdoor air levels of particulate matter ≤10µm (PM10) from motorized traffic at geocoded subjects’ residence. RESULTS: In crude analysis, regression beta coefficients for dietary Cd, smoking and PM10 on serum Cd levels were 0.03 (95% CI -0.83 to 0.88), 6.96 (95% CI -0.02 to 13.95) and 0.62 (95% CI -0.19 to 1.43), respectively. In the adjusted analysis, regression beta coefficients were -0.34 (95% CI -1-40 to 0.71), 5.81 (95% CI -1.43 to 13.04) and 0.47 (95% CI -0.35 to 1.29), respectively. CONCLUSION: Cigarette smoking was the most important factor influencing serum Cd in our non-occupationally exposed population, as expected, while dietary Cd was not associated with this biomarker. Outdoor air pollution, as assessed through exposure to particulate matter generated by motorized traffic, was an additional source of Cd exposure.

Original article: Long-term mortality patterns in a residential cohort exposed to inorganic selenium in drinking water

Vinceti M, Ballotari P, Steinmaus C, Malagoli C, Luberto F, Malavolti M, Giorgi Rossi P.

Environ Res. 2016 2016 Oct;150:348-356

Abstract

Selenium (Se) is a metalloid of considerable nutritional and toxicological importance in humans. To date, limited epidemiologic evidence exists about the health effects of exposure to this trace element in drinking water. We investigated the relationship between Se levels in water and mortality in the municipality of Reggio Emilia, Italy, where high levels of Se were previously observed in drinking water. From 1974 to 1985, 2065 residents consumed drinking water with Se levels close to the European standard of 10μg/l, in its inorganic hexavalent form (selenate). Follow-up was conducted for the years 1986-2012 in Reggio Emilia and a lesser exposed comparison group of around 100,000 municipal residents, with comparable socio-demographic characteristics. Overall mortality from all causes, cardiovascular disease and cancer showed little evidence of differences. However, excess rate ratios were seen for some site specific cancers such as neoplasms of buccal cavity and pharynx, urinary tract, lymphohematopoietic tissue, melanoma, and two neurodegenerative diseases, Parkinson’s disease and amyotrophic lateral sclerosis. Excess mortality in the exposed cohort for specific outcomes was concentrated in the first period of follow-up (1986-1997), and waned starting 10 years after the high exposure ended. We also found lower mortality from breast cancer in females during the first period of follow-up. When we extended the analysis to include residents who had been consuming the high-selenium drinking water for a shorter period, mortality rate ratios were also increased, but to a lesser extent. Overall, we found that the mortality patterns related to long-term exposure to inorganic hexavalent selenium through drinking water were elevated for several site-specific cancers and neurodegenerative disease.

 

Dietary reference values for potassium

EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA), Dominique Turck, Jean-Louis Bresson, Barbara Burlingame, Tara Dean, Susan Fairweather-Tait, Marina Heinonen, Karen Ildico Hirsch-Ernst, Inge Mangelsdorf, Harry McArdle, Monika Neuhauser-Berthold, Gra_zyna Nowicka, Kristina Pentieva, Yolanda Sanz, Alfonso Siani, Anders Sjodin, Martin Stern, Daniel Tome, Henk Van Loveren, Marco Vinceti, Peter Willatts, Peter Aggett, Ambroise Martin, Hildegard Przyrembel, Anja Bronstrup, Janusz Ciok, Jose Angel Gomez Ruiz, Agnes de Sesmaisons-Lecarre and Androniki Naska

EFSA Journal 2016;14(10):4592

Abstract

Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) derives dietary reference values (DRVs) for potassium. The Panel decides to set DRVs on the basis of the relationships between potassium intake and blood pressure and stroke. The Panel considers that randomised controlled trials and an observational cohort study carried out in a European adult population provide evidence that a potassium intake of 3,500 mg (90 mmol)/day has beneficial effects on blood pressure in adults. Furthermore, there is consistent evidence from observational cohort studies that potassium intakes below 3,500 mg/day are associated with a higher risk of stroke. Available data cannot be used to determine the average requirement of potassium but can be used as a basis for deriving an adequate intake (AI). A potassium intake of 3,500 mg/day is considered adequate for the adult population and an AI of 3,500 mg/day for adult men and women is proposed. For infants and children, the AIs are extrapolated from the AI for adults by isometric scaling and including a growth factor. An AI of 750 mg (19 mmol)/day is set for infants aged 7–11 months. For children, AIs from 800 mg (20 mmol)/day (1–3 years old) to 3,500 mg/day (15–17 years old) are set. Considering that the daily accretion rate of potassium in fetal and maternal tissues can be met by the adaptive changes which maintain potassium homeostasis during pregnancy, the AI set for adults applies to pregnant women. For lactating women, the amount of potassium needed to compensate for the losses of potassium through breast milk is estimated and an AI of 4,000 mg (102 mmol)/day is proposed.

Link to the EFSA news

Link to the paper