Association of soil potassium and sodium concentrations with spatial disparities of prevalence and mortality rates of hypertensive diseases in the USA

Impact of Selenium on Biomarkers and Clinical Aspects Related to Ageing. A Review

Selenium (Se) is an essential dietary trace element that plays an important role in the prevention of inflammation, cardiovascular diseases, infections, and cancer. Selenoproteins contain selenocysteine in the active center and include, i.a., the enzymes thioredoxin reductases (TXNRD1–3), glutathione peroxidases (GPX1–4 and GPX6) and methionine sulfoxide reductase, involved in immune functions, metabolic homeostasis, and antioxidant defense. Ageing is an inevitable process, which, i.a., involves an imbalance between antioxidative defense and reactive oxygen species (ROS), changes in protein and mitochondrial renewal, telomere attrition, cellular senescence, epigenetic alterations, and stem cell exhaustion. These conditions are associated with mild to moderate inflammation, which always accompanies the process of ageing and age-related diseases. In older individuals, Se, by being a component in protective enzymes, operates by decreasing ROS-mediated inflammation, removing misfolded proteins, decreasing DNA damage, and promoting telomere length. Se-dependent GPX1–4 and TXNRD1–3 directly suppress oxidative stress. Selenoprotein H in the cell nucleus protects DNA, and selenoproteins residing in the endoplasmic reticulum (ER) assist in the removal of misfolded proteins and protection against ER stress. In this review, we highlight the role of adequate Se status for human ageing and prevention of age-related diseases, and further its proposed role in preservation of telomere length in middle-aged and elderly individuals.

Comparations of major and trace elements in soil, water and residents' hair between longevity and non-longevity areas in Bama, China

Natural environment is an important factor affecting longevity. Soil, water and hair samples from Bama were assayed to investigate the effects of elements on the regional longevity. The concentrations of Cd, Co and Mg in soil and Co in drinking water were significantly higher in longevity area than those in non-longevity area (p < 0.05). The concentrations of K, Mo, Na, Pb and V in soil, Mg, Na, Fe, Li and Mn in drinking water and I, K, Mg, Mn, Na and Sr in hair were significantly lower in longevity area than those in non-longevity area (p < 0.05). Mg, Mn, Na and Sr in hair were affected by soil and drinking water. Our results indicate that adequate concentration of Mg in soil might benefit longevity, excessive concentrations of Na in soil, Mg, Mn and Na in drinking water and Mg, Mn, Na and Sr in hair might reduce lifespan of local residents.

Potassium physiology from Archean to Holocene: A higher-plant perspective

In this paper, we discuss biological potassium acquisition and utilization processes over an evolutionary timescale, with emphasis on modern vascular plants. The quintessential osmotic and electrical functions of the K⁺ ion are shown to be intimately tied to K⁺-transport systems and membrane energization. Several prominent themes in plant K⁺-transport physiology are explored in greater detail, including: (1) channel mediated K⁺ acquisition by roots at low external [K⁺]; (2) K⁺ loading of root xylem elements by active transport; (3) variations on the theme of K⁺ efflux from root cells to the extracellular environment; (4) the veracity and utility of the "affinity" concept in relation to transport systems. We close with a discussion of the importance of plant-potassium relations to our human world, and current trends in potassium nutrition from farm to table.

Rising Trend of Hypokalemia Prevalence in the US Population and Possible Food Causes

Background: Potassium intake deficiency is a chronic issue in the US and many other countries. Possible causes of the deficiency are understudied.Objective: This study examined potassium deficiency in the US population and possible causes for the new trend.Methods: Serum potassium data of 28,379 men and 29,617 women between ages 12 and 80 years old who participated in the US National Health and Nutrition Examination Survey (NHANES) between 1999 and 2016 were examined. Blood samples were collected by NHANES and blood biochemistry data were measured in designed laboratories. The data were released bi-annually. Possible causes of low potassium intakes were explored.Results: There was an apparent decline of serum potassium in the US population between ages 12 and 80 years from 1999 to 2016. Annual average serum potassium concentrations changed from 4.14 ± 0.01 to 3.97 ± 0.01 mmol/l during this period. Hypokalemia prevalence in the US rose from 3.78%±0.68% to 11.06%±1.08% during this period with a higher hypokalemia prevalence in non-Hispanic black than in non-Hispanic white persons. It is possible that declining potassium concentration in food sources in the US contributed to lower potassium intake and increasing potassium deficiency.Conclusion: The rising trend of hypokalemia prevalence in the US population between 1999 and 2016 is alarming. Renewed efforts to reduce potassium intake deficiency in the US at population level are needed. The impact of possible decreasing crop available potassium levels and increasing consumption of processed food on the potassium deficit trend in the US are possible explanations for the rise in hypokalemia prevalence and require further study.

Comparison of methods for addressing the point-to-area data transformation to make data suitable for environmental, health and socio-economic studies

Soil lead (Pb) provides an important exposure pathway to the human body through soil ingestion and dust inhalation and is closely associated with human health as well as social behaviour. The challenge of transforming different spatial supports arises when linking point data (Pb concentration) to areal data (health status or social behaviour). A detailed review of methodologies for integrating point and areal data has been carried out. Among a number of methodologies, eight methods: (1) average, (2) median, (3) centroids inverse distance weighted (IDW), (4) average block IDW, (5) median block IDW, (6) centroids ordinary kriging (OK), (7) average block OK and (8) median block OK, have been compared using Pb data set in the Greater London Authority (GLA) area. The results indicated that the method of median block IDW was recommended for further investigation of the relationship between Pb concentration and socio-economic factors in the ward-level of the GLA area. The reasons were (i) spatial interpolations were useful for predicting unobserved values when simple average and median could not work in the locations where there were no samples collected in some areal units; (ii) the median value was more suitable than the average value for a skewed data set; (iii) the block method reduced estimation error and provided more representative values of areal units than the centroid method; (iv) IDW reserved more spatial variation than OK, containing more local maxima (hotspot) and local minima. Despite that it is still hard to decide the optimal method, this study has highlighted the point-to-area transformation issue and provided valuable examples to compare the different methods.

Blood pressure and burden of hypertension in Cameroon, a microcosm of Africa: a systematic review and meta-analysis of population-based studies

OBJECTIVE

To estimate national and geography-based variations in blood pressure and burden of hypertension in Cameroon, generally called 'miniature Africa'.

METHODS

PubMed, Medline, EMBASE, CINHAL, Web of Science, Popline, Scopus and BDSP were searched through November 2018, for hypertension studies among Cameroonians aged at least 18 years. Hypertension was measured as SBP at least 140 mmHg or DBP at least 90 mmHg. Random-effects meta-analysis was used.

RESULTS

Twenty studies involving 46 491 participants met inclusion criteria. Overall hypertension prevalence was 30.9% [95% confidence interval (CI) 27.0-34.8]: 29.6% (24.1-35.1) and 32.1% (27.2-37.1) in 1994-2010 and 2011-2018, respectively. Of hypertensive participants, only 24.4% (18.9-30.0) - 31.6% (21.0-42.3) and 20.8% (14.0-27.7) in 1994-2010 and 2011-2018, respectively - were aware of their status, 15.1% (10.6-19.6) were taking antihypertensive medications and 8.8% (5.7-11.9) - 10.4% (7.5-13.3) and 8.3% (4.4-12.3) in 1994-2010 and 2011-2018, respectively - were controlled. Hypertension prevalence varied by sex: 34.3% (30.0-38.6) for men and 31.3% (26.5-36.1) for women; ethnicity: from 3.3% (0.4-6.2) among Pygmies to 56.6% (49.4-63.8) among Bamileke; urbanity: 25.4% (17.1-33.7) for rural and 31.4% (27.3-35.5) for urban dwellers; agroecological zone: from 35.1% (28.9-41.3) in Tropical highlands to 28% (20.1-35.9) in Guinea-Savannah; and subnational region: from 36.3% (27.8-44.9) in the West to 17.1% (9.9-44.2) in the South.

CONCLUSION

Cameroon's hypertension prevalence is high and increasing whereas awareness, treatment and control are low and declining. Emerging patterns call urgently for effective campaigns to raise hypertension awareness alongside strategies for hypertension prevention and BP control.