Impact of Hot Environment on Fluid and Electrolyte Imbalance, Renal Damage, Hemolysis, and Immune Activation Postmarathon

Effects of low protein diets on acid-base balance, electrolyte balance, intestinal structure, and amino acid transport in piglets

Reducing the dietary crude protein (CP) could effectively reduce pressure on protein ingredient supplies. However, few data have been reported about the extent to which CP can be reduced and whether limiting the use of soybean meal leads to electrolyte imbalance. In this experiment, using the low protein (LP) diet [2% lower than NRC (2012)], seventy-two piglets (35 days old) were randomly divided into 2 groups with 6 replicates of 6 piglets each: CON group (CP = 18.5%) and LP group (CP = 16.5%), to investigate the effect of the LP diet on electrolyte balance, acid-base balance, intestinal structure and amino acid transport in piglets. The results revealed that the LP diet decreased the average daily gain and dietary CP digestibility, and damaged the villi structure of the small intestine. Compared with the CON diet, the potassium content decreased and the chlorine content increased in the LP diet, and similar trends were shown in piglet serum. The arterial pH, pCO2, HCO3 -, and base excess of piglets in the LP group were lower than those in the CON group, while pO2 was higher than those in the CON group. Interestingly, the LP diet significantly increased the lysine content in piglet serum and significantly decreased the levels of arginine, leucine, and glutamic acid. Furthermore, the LP diet significantly affected the expression of some amino acid transport vectors (B0AT1, EAAC1, and y+LAT1). In summary, these findings suggested that the LP diet leads to acid-base imbalance, amino acid transport disorder and amino acids imbalance in piglets, and the dietary electrolyte may be a key factor in the impact of the LP diet on piglet growth performance and intestinal health.

Dysnatremia in a changing climate: A global systematic review of the association between serum sodium and ambient temperature

OBJECTIVE

Both hyponatremia and hypernatremia have been reported to occur more frequently with higher ambient temperatures, although the underlying mechanisms are not well understood. Global temperatures are rising due to climate change, which may impact the incidence of dysnatremia worldwide. We aimed to identify, collate and critically appraise studies analyzing the relationship between climate measures (outdoor temperature, humidity) and serum sodium concentrations.

DESIGN

Systematic review, reported in accordance with PRISMA guidelines.

METHODS

MEDLINE and Embase were searched with relevant key terms. Studies assessing the effect on serum sodium measurement of elevated temperature or humidity versus a comparator were included.

RESULTS

Of 1466 potentially relevant studies, 34 met inclusion criteria, originating from 23 countries spanning all inhabited continents. The majority (30 of 34, 88%) reported a significant association between outdoor temperature and dysnatremia, predominantly lower serum sodium with increased ambient temperature. Humidity had a less consistent effect. Individuals aged above 65 years, children, those taking diuretics and antidepressants, those with chronic renal impairment or those undertaking physical exertion had increased vulnerability to heat-associated dysnatremia. The risk of bias was assessed to be high in all but four studies.

CONCLUSIONS

Higher ambient temperature is consistently associated with an increased incidence of hyponatremia. We infer that hyponatremia presentations are likely to rise with increasing global temperatures and the frequency of extreme heat events secondary to climate change. Evidence-based public health messages, clinician education and reduction in fossil fuel consumption are necessary to reduce the expected burden on healthcare services worldwide.

Effects of Different Hydration Strategies in Young Men during Prolonged Exercise at Elevated Ambient Temperatures on Pro-Oxidative and Antioxidant Status Markers, Muscle Damage, and Inflammatory Status

Physical exercise is associated with an increase in the speed of metabolic processes to supply energy to working muscles and endogenous heat production. Intense sweating caused by the work performed at high ambient temperatures is associated with a significant loss of water and electrolytes, leading to dehydration. This study aimed to examine the effectiveness of different hydration strategies in young men during prolonged exercise at elevated ambient temperatures on levels of pro-oxidative and antioxidant status, oxidative status markers (TAC/TOC), muscle cell damage (Mb, LDH), and inflammatory status (WBC, CRP, IL-1β). The study was conducted on a group of 12 healthy men with average levels of aerobic capacity. The intervention consisted of using various hydration strategies: no hydration; water; and isotonic drinks. The examination was di-vided into two main stages. The first stage was a preliminary study that included medical exami-nations, measurements of somatic indices, and exercise tests. The exercise test was performed on a cycle ergometers. Their results were used to determine individual relative loads for the main part of the experiment. In the second stage, the main study was conducted, involving three series of weekly experimental tests using a cross-over design. The change in plasma volume (∆PV) measured im-mediately and one hour after the exercise test was significantly dependent on the hydration strategy (p = 0.003 and p = 0.002, respectively). The mean values of oxidative status did not differ signifi-cantly between the hydration strategy used and the sequence in which the test was performed. Using isotonic drinks, due to the more efficient restoration of the body’s water and electrolyte balance compared to water or no hydration, most effectively protects muscle cells from the negative effects of exercise, leading to heat stress of exogenous and endogenous origin.

The impact of heat on kidney health: A PRISMA-compliant bibliometric analysis

BACKGROUND

Exposure to excessive heat can impact kidney health. Climate change is projected to aggravate this impact. An analysis of articles published between 1958 and 2021 was conducted to explore the progress of the research on this issue.

METHODS

This study included a bibliometric analysis wherein Web of Science was used to generate a list of all published articles related to the impact of heat on kidney health. Basic information about the articles, such as titles, authors' names, keywords, and citations, were recorded and analyzed.

RESULTS

A total of 226 published articles related to the impact of heat on kidney health were identified as of November 20, 2021. Most of these articles (93%) were published within the last decade. The United States was the most prominent country in terms of research productivity and collaboration. Researchers from the United States were well represented among the top 20 contributors of published articles on the study issue. The productivity of the top 20 authors varied between 6 and 32 articles each. A total of 25 common words used by the authors were identified. The most frequently used keywords were chronic kidney disease, heat stress, acute kidney injury, Mesoamerican nephropathy, and climate change. Keyword analysis revealed 3 distinct major research clusters in the existing scientific research on the impact of heat on kidney health: chronic kidney disease of unknown etiology, heat stress and renal physiology, and the effect of climate change on kidney health.

CONCLUSIONS

Research on heat-related kidney injury has witnessed rapid development in recent decades, motivated by the emergence of chronic kidney disease of unknown etiology and climate change. Developing countries in hot regions must increase their productivity in this research area through international collaboration and partnerships.

The Effect of Heat Stress and Vitamin and Micro-Mineral Supplementation on Some Mineral Digestibility and Electrolyte Balance of Pigs

Heat stress (HS) can have detrimental effects on intestinal integrity and can jeopardize the digestibility performance in pigs. With prolonged exposure to heat, some thermoregulatory processes in pigs are potential causes for electrolyte imbalance. The adverse effects of HS on mineral digestibility and electrolyte balance are not widely studied and information on its abatement through vitamin and micro-mineral supplementation in combinations above the recommended level in pigs is limited. The aim of this study is to research this area. Thirty-six Danbred hybrid barrows (65.1 ± 2.81kg) were distributed among the four treatments (n = 9 per treatment): (1) thermo-neutral (19.5 ± 0.9 °C, RH- 85.9 ± 7.3%)+ control diet (TC) (NRC, 2012), (2) HS (28.9 ± 0.9 °C, RH- 60.4 ± 4.3%) + control diet (HC), (3) HS +diet with elevated levels of vitamins (vitamin E and C) and micro-minerals (Zn and Se) (HT1), and (4) HS + diet with further elevation of vitamins and micro-minerals (HT2). Plasma samples were collected on days 7 and 21 of the experiment to investigate electrolyte concentration. During the experimental period, feces samples were collected from pigs placed in digestibility cages (six pigs from each treatment) to investigate the digestibility of Ca, P, Na, Se, and Zn. HS did not decrease the digestibility of minerals, but elevated supplementation of the selected vitamins and trace minerals improved it significantly. HS caused a significant decrease of Cl- (p < 0.01) in plasma, indicating an imbalance. In conclusion, pigs can have some resilience against heat stress in terms of mineral digestibility. Proper vitamin and trace mineral supplementation are key factors in the ability of pigs to overcome the negative effects of HS.

Effect of Multiple-Nutrient Supplement on Muscle Damage, Liver, and Kidney Function After Exercising Under Heat: Based on a Pilot Study and a Randomised Controlled Trial

Objective: This study explored the effect of multiple-nutrient supplementation on muscle damage and liver and kidney function after vigorous exercise under heat.

Methods: After an initial pilot trial comprising 89 male participants, 85 participants were recruited and assigned into three groups: a multiple-nutrient (M) group, a glucose (G) group, and a water (W) group. Multiple-nutrient supplements contain glucose, fructose, maltose, sodium, potassium, vitamin B₁, vitamin B₂, vitamin C, vitamin K, and taurine. Participants were organised to take a 3-km running test (wet-bulb globe temperature 32°C) after a short-term (7 days) supplement. Blood samples were obtained to detect biochemical parameters [glucose (GLU), aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN), uric acid (UA), creatinine (Cr), creatine kinase (CK), lactate dehydrogenase (LDH), and lactic acid], inflammation factors [interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α)], and oxidative stress biomarkers [superoxide dismutase (SOD) and 8-iso-prostaglandin F (2alpha) (8-iso-PGF2α)].

Results: In the pilot trial, BUN decreased significantly in the M and G groups immediately after the running test. AST, Cr, and UA were significantly reduced 24 h after the running test with single-shot multiple-nutrient supplementation. In the short-term trial, multiple nutrients further prevented the elevation of CK (p = 0.045) and LDH (p = 0.033) levels 24 h after strenuous exercise. Moreover, we found that multiple nutrients significantly reduced IL-6 (p = 0.001) and TNF-α (p = 0.015) elevation immediately after exercise. Simultaneously, SOD elevation was significantly higher in the M group immediately after exercising than in the other two groups (p = 0.033). 8-iso-PGF2α was reduced in the M group 24 h after exercise (p = 0.036).

Conclusions: This study found that multiple-nutrient supplementation promoted the recovery of muscle damage and decreased liver and kidney function caused by strenuous exercise in a hot environment, probably through the inhibition of secondary damage induced by increased inflammatory reactions and oxidative stress. In this respect, the current study has important implications for the strategy of nutritional support to accelerate recovery and potentially prevent heat-related illness. This study was prospectively registered on clinicaltrials.gov on June 21, 2019 (ID: ChiCTR1900023988).

Effects of Monomeric and Oligomeric Flavanols on Kidney Function, Inflammation and Oxidative Stress in Runners: A Randomized Double-Blind Pilot Study

Nonsteroidal anti-inflammatory drugs are frequently used by athletes in order to prevent musculoskeletal pain and improve performance. In combination with strenuous exercise, they can contribute to a reduction of renal blood flow and promote development of kidney damage. We aimed to investigate whether monomeric and oligomeric flavanols (MOF) could reduce the severity of kidney injuries associated with the intake of 400-mg ibuprofen followed by the completion of a half-marathon in recreational athletes. In this double-blind, randomized study, the original MOF blend of extracts from grape seeds (Vitis vinifera L.) and pine bark (Pinus pinaster L.) or placebo were taken for 14 days preceding the ibuprofen/half-marathon. Urine samples were collected before and after the ibuprofen/half-marathon, and biomarkers of kidney injury, inflammation and oxidative stress were assessed. Intake of MOF significantly reduced the incidence of post-race hematuria (p = 0.0004) and lowered concentrations of interleukin (IL)-6 in the urine (p = 0.032). Urinary neutrophil-associated lipocalin, creatine, albumin, IL-8 and malondialdehyde tended to decrease. The supplementation with MOF in recreational runners appears to safely preserve kidney function, reduce inflammation and promote antioxidant defense during strenuous exercise and intake of a single dose of ibuprofen.

Long distance training associated to HIIT protocol does not induce changes in blood biochemical markers in adult marathoners

ABSTRACT Objective: to verify blood markers during a 12-week training protocol and after Sao Paulo Marathon. Methods: Blood samples of 9 male marathoners were collected before (C1) and after (C2) 12-week training protocol, before (C3) and after (C4) marathon. Muscle and liver damage markers (creatine kinase [CK-MM], aspartate aminotransferase [AST], alanine aminotransferase [ALT]), oxidative stress levels (thiobarbituric acid reactive substances [TBARS]) and serum iron concentration were measured. Results: changes were identified comparing moment C4 to other moments for CK-MM and iron. For AST, ALT, and TBARS no differences were identified. Conclusion: strenuous exercises might elicit changes on blood markers, needing follow up strategies to avoid impairments to athletes’ performance and health.

Acute vascular insufficiency of intestine: incidence highest in summer, outcomes worst in winter

BACKGROUND

The incidence of acute vascular insufficiency of intestine (AVII) is on the rise in the USA and is associated with significant morbidity and mortality. Seasonal variations have been observed in the onset of several gastrointestinal diseases. It is thus far unknown whether the incidence, in-hospital mortality rates, and length of hospital stay (LOS) of AVII vary in different seasons.

AIMS

The aims of this study were to study the seasonal variations in the (1) incidence, (2) in-hospital mortality, and (3) LOS of AVII in the USA.

METHODS

We used the Nationwide Inpatient Sample to identify patients aged ≥ 18 years hospitalized from the years 2000-2014. We used the Edwards recognition with estimation of cyclic trend method to study the seasonal variation of AVII hospitalizations and z test to compare the seasonal incidences (peak-to-low ratio), mortalities, and LOS.

RESULTS

A total of 1,441,447 patients were hospitalized with AVII (0.3% of all hospitalizations). Patients with AVII were older (69.0 ± 0.1 vs 56.9 ± 0.1) and more commonly females (65.4% vs 35.5%) than patients without AVII (p < 0.001). The incidence of AVII increased through the summer to peak in September (peak/low ratio 1.028, 95% CI 1.024-1.033, p < 0.001). Patients with AVII hospitalized in winter had the highest mortality (17.3%, p < 0.001) and LOS (9.2 ± 0.7 days, p < 0.001).

CONCLUSIONS

The incidence of AVII in the USA peaks in late summer. The in-hospital mortality rates and LOS associated with AVII are the highest in winter. Physicians could be cognizant of the seasonal variations in the incidence, in-hospital mortality, and LOS of AVII.

Association of Daily Dietary Intake and Inflammation Induced by Marathon Race

Daily food intake is crucial to maintain health and determine endogenous fuel to practice endurance exercise. We investigated the association between quantity of macronutrient and micronutrient daily intake and inflammation induced by long-distance exercise. Methods. Forty-four Brazilian male amateurs' marathon finishers from 30 to 55 years old participated in this study. Blood samples were collected 1 day before, immediately after, and 1 day and 3 days after São Paulo International Marathon. The serum levels of IL-6, IL-1β, IL-10, IL-8, IL-12p70, and TNF-α were measured to evaluate inflammation. Dietary intake was determined using a prospective method of three food records in the week before marathon race. Results. Marathon race promoted an elevation on IL-6, IL-8, IL-1-β, and IL-10 immediately after the race. The energy intake (EI), carbohydrate, fiber, folic acid, vitamin E, vitamin D, calcium, magnesium, and potassium intakes was below recommended. Immediately after the marathon race, we observed a negative correlation between IL-8 and daily EI, carbohydrate, fiber, fat, iron, calcium, potassium, and sodium intakes, and higher levels of IL-8 on runners with <3 g/kg/day of carbohydrate intake compared to runners with >5 g/kg/day. We demonstrated a positive correlation between daily carbohydrate intake and IL-10 and a negative correlation between TNF-α and % of energy intake recommended, carbohydrate and fiber intakes. Finally, runners with adequate EI had lower levels of IL-1β and TNF-α compared with low EI immediately after the race. Conclusion. Nutrition strategies to promote balanced diet in amateur runners seem to be as important as immunonutrition sports market. Daily food intake, mainly EI, electrolyte and carbohydrate intakes, may modulate exacerbated inflammation after endurance exercise.

Quick Recovery of Renal Alterations and Inflammatory Activation after a Marathon

Purpose

We evaluated the incidence of acute kidney injury in a cohort of marathon participants.

Methods

We conducted a prospective observational study focused on evaluating the incidence of kidney damage after a marathon, and its evolution in the first 48 h after the marathon in 88 runners who completed the Valencia Marathon.

Results

From the 88 participants, 42 (48.28%) presented with acute kidney injury, mainly grade 1 (95.20%). Microscopic haematuria was observed in 29 runners (33%). Levels of interleukin 6, leukocytes, and neutrophils were markedly increased at the marathon's finish line.

Conclusions

Our results confirmed that there are slight transient changes in glomerular filtration rate and inflammatory activation after a marathon.

Athletes with neurologic disease

Neurologic disease does not discriminate, even among athletes. Common neurologic diseases among athletes include multiple sclerosis, seizures, headaches, and sleep disorders. Although concrete guidelines for sport participation among athletes with neurologic diseases do not exist, evidence-based and consensus statements can aid healthcare providers in determining whether and to what extent such athletes should participate in sports. Moreover, sport participation is important, since multiple studies indicate that exercise improves disease-specific symptoms, manifestations, and overall quality of life. Although some risk is involved for athletes with neurologic disease, risk is mitigated with proper supervision and neurologic oversight, disease-specific accommodations, and counseling of the athletic staff and the athletes. Neurologic oversight entails an initial comprehensive neurologic assessment by a neurologist followed by regular follow-up. Preparation for environmental conditions encountered by athletes with neurologic disease will further improve safety during their participation in sport. With sound recommendations, neurologic oversight, and proper supervision, most athletes with neurologic disease can participate in athletics. The health benefits that they will gain from participation in athletics outweigh the risks.