Medication management during risk of dehydration: A qualitative study among elderly patients with impaired renal function and informal caregivers

BACKGROUND

Patients with impaired renal function are at an increased risk of dehydration due to vomiting, diarrhoea or fever (so-called sick days). Temporary medication adjustment during sick days is necessary and current initiatives and information materials for patients are available. However, the knowledge, experiences and information needs of patients and informal caregivers about sick day guidance are unknown.

AIM

To gain insight into the understanding of safe medication use during periods of dehydration risk in elderly patients with impaired renal function and their informal caregivers.

DESIGN AND SETTING

Qualitative interview study with patients with impaired renal function and unrelated informal caregivers from three community pharmacies in the Netherlands.

METHOD

The interviews were conducted by telephone or live by two researchers in November 2020-September 2021 and audiotaped and transcribed verbatim. The coding of transcripts was performed deductively and inductively in Nvivo 12, a thematic analysis was applied.

RESULTS

In total 12 patients and 11 unrelated informal caregivers were included. Three main themes were derived from the interview guide and subthemes emerged from the transcripts. The included patients and informal caregivers had limited knowledge about medication management during sick days. In contrast to patients, informal caregivers seemed interested in a medication management protocol for sick days.

CONCLUSION

Patients with impaired renal function and informal caregivers have little knowledge about and experience with dehydration and safe use of medication during sick days. General practitioners and pharmacists should involve the care network, including informal caregivers, when implementing sick day guidance.

Climate change's implications for practice: Pharmacologic considerations of heat-related illness

ABSTRACT

Climate change is the greatest threat to global health. As climate change worsens, heat waves will be longer, more intense, and more frequent. Increased health risks from climate change and heat waves include heat-related illness (HRI). HRI increases ED visits, hospitalizations, and mortality. Healthcare providers should be aware of the impact of medications on risk for HRI. This article elucidates signs and symptoms, populations at risk, drugs and mechanisms that increase risk, and patient education to reduce risk.

Heat wave exposure and increased heat-related hospitalizations in young children in South Korea: A time-series study

BACKGROUND

Numerous studies have investigated the association between heat wave exposure increased heat-related hospitalizations in the general population. However, little is known about heat-related morbidity in young children who are more vulnerable than the general population. Therefore, we aimed to evaluate the association between hospitalization for heat-related illness in children and heat wave exposure in South Korea.

METHODS

We used the National Health Insurance Service (NHIS) database, which provides medical records from 2015 to 2019 in South Korea. We defined daily hospitalizations for heat-related illness of children younger than five years during the summer period (June to August). We considered the definition of heat waves considering the absolute temperature and percentile. A total of 12 different heat waves were used. A time-series analysis was used to investigate the association between heat wave exposure and heat-related hospitalization among children younger than five years. We used a two-stage design involving a meta-analysis after modeling by each region.

RESULTS

We included 16,879 daily heat-related hospitalizations among children younger than five years. Overall, heat wave exposure within two days was most related for heat-related hospitalizations in young children. The relative risk (RR) due to heat wave exposure within two days (lag2) (12 definitions: 70th to 90th percentile of maximum temperature) ranged from 1.038 (95% confidence interval (CI): 0.971, 1.110) to 1.083 (95% CI: 1.036, 1.133). We found that boys were more vulnerable to heat exposure than girls. In addition, we found that urban areas were more vulnerable to heat exposure than rural areas.

CONCLUSIONS

In our study, heat wave exposure during summer was found to be associated with an increased risk of hospitalization for heat-related illness among children younger than five years. Our findings suggest the need for summer heat wave management and prevention for children.

Effects of Medications on Heat Loss Capacity in Chronic Disease Patients: Health Implications Amidst Global Warming

Pharmacological agents used to treat or manage diseases can modify the level of heat strain experienced by chronically ill and elderly patients via different mechanistic pathways. Human thermoregulation is a crucial homeostatic process that maintains body temperature within a narrow range during heat stress through dry (i.e., increasing skin blood flow) and evaporative (i.e., sweating) heat loss, as well as active inhibition of thermogenesis, which is crucial to avoid overheating. Medications can independently and synergistically interact with aging and chronic disease to alter homeostatic responses to rising body temperature during heat stress. This review focuses on the physiologic changes, with specific emphasis on thermolytic processes, associated with medication use during heat stress. The review begins by providing readers with a background of the global chronic disease burden. Human thermoregulation and aging effects are then summarized to give an understanding of the unique physiologic changes faced by older adults. The effects of common chronic diseases on temperature regulation are outlined in the main sections. Physiologic impacts of common medications used to treat these diseases are reviewed in detail, with emphasis on the mechanisms by which these medications alter thermolysis during heat stress. The review concludes by providing perspectives on the need to understand the effects of medication use in hot environments, as well as a summary table of all clinical considerations and research needs of the medications included in this review. SIGNIFICANCE STATEMENT: Long-term medications modulate thermoregulatory function, resulting in excess physiological strain and predisposing patients to adverse health outcomes during prolonged exposures to extreme heat during rest and physical work (e.g., exercise). Understanding the medication-specific mechanisms of altered thermoregulation has importance in both clinical and research settings, paving the way for work toward refining current medication prescription recommendations and formulating mitigation strategies for adverse drug effects in the heat in chronically ill patients.

Gastrointestinal cell injury and perceived symptoms after running the Boston Marathon

Gastrointestinal (GI) disturbances are a prevalent cause of marathon related complaints, and in extreme cases can promote life-threatening conditions such as exertional heat stroke. Our aim was to study intestinal cell injury [via intestinal fatty acid binding protein (I-FABP)] and perceived GI distress symptoms among marathon runners. We also examined potential risk factors (e.g., inadequate sleep) that could exacerbate GI disturbances in healthy, trained endurance runners. This was a parallel mixed-methods study design. 2019 Boston Marathon participants were recruited via email and subjects completed surveys before the race describing demographics and training history. Participants completed a GI questionnaire to assess presence and severity of symptoms, a survey regarding risk factors (e.g., recent illness, medications) that could promote GI disturbances, and provided a urine sample at three time points (immediately pre-race, post-race, and 24-h post-race). Due to weather, blood samples were only collected immediately and 24-h post-race. A total of 40 runners (males: n = 19, age = 44.9 ± 10.8 years; females: n = 21, age = 44.8 ± 10.6 years) completed this study. I-FABP significantly decreased from post-race (3367.5 ± 2633.5 pg/mL) to 24-h post-race (1657.3 ± 950.7 pg/mL, t (39) = -4.228, p < .001, d = -.669). There was a significant difference in overall GI symptom scores across the three time points (F (2, 39) = 41.37, p < .001). The highest average score occurred post-race (.84 ± .68), compared to pre-race (.09 ± .12) and 24-h post-race (.44 ± .28). Post-race I-FABP (r = .31, p = .048) and post-race urine specific gravity (r = .33, p = .041) were significantly correlated with post-race GI symptom scores. Our study provides further support to the individualized nature of GI disturbances, with participants experiencing a wide range of risk factors that can influence the extent of GI damage and perceived symptoms during and after exercise.

Climate Change, Skin Health, and Dermatologic Disease: A Guide for the Dermatologist

Climate change has a pervasive impact on health and is of clinical relevance to every organ system. Climate change-related factors impact the skin's capacity to maintain homeostasis, leading to a variety of cutaneous diseases. Stratospheric ozone depletion has led to increased risk of melanoma and keratinocyte carcinomas due to ultraviolet radiation exposure. Atopic dermatitis, psoriasis, pemphigus, acne vulgaris, melasma, and photoaging are all associated with rising levels of air pollution. Elevated temperatures due to global warming induce disruption of the skin microbiome, thereby impacting atopic dermatitis, acne vulgaris, and psoriasis, and high temperatures are associated with exacerbation of skin disease and increased risk of heat stroke. Extreme weather events due to climate change, including floods and wildfires, are of relevance to the dermatologist as these events are implicated in cutaneous injuries, skin infections, and acute worsening of inflammatory skin disorders. The health consequences as well as the economic and social burden of climate change fall most heavily on vulnerable and marginalized populations due to structural disparities. As dermatologists, understanding the interaction of climate change and skin health is essential to appropriately manage dermatologic disease and advocate for our patients.

The mental health of women and climate change: Direct neuropsychiatric impacts and associated psychological concerns

Climate change brings exposures to heat, air pollution, poorer quality food, and infectious disease that have significant direct effects on women and their mental health. These environmental impacts are multifaceted in their consequences and raise risks of depression, suicide, violent victimization, post-traumatic stress disorder, and various other neuropsychiatric symptoms. Women also suffer increased climate psychological risks from higher rates of stillbirth, preterm birth, and developmental problems in their children. Here we review what is known about the overlap of women's individual mental health and climate change, and highlight areas where more research is needed.

Climate change and the prevention of cardiovascular disease

Climate change is a worsening global crisis that will continue negatively impacting population health and well-being unless adaptation and mitigation interventions are rapidly implemented. Climate change-related cardiovascular disease is mediated by air pollution, increased ambient temperatures, vector-borne disease and mental health disorders. Climate change-related cardiovascular disease can be modulated by climate change adaptation; however, this process could result in significant health inequity because persons and populations of lower socioeconomic status have fewer adaptation options. Clear scientific evidence for climate change and its impact on human health have not yet resulted in the national and international impetus and policies necessary to slow climate change. As respected members of society who regularly communicate scientific evidence to patients, clinicians are well-positioned to advocate on the importance of addressing climate change. This narrative review summarizes the links between climate change and cardiovascular health, proposes actionable items clinicians and other healthcare providers can execute both in their personal life and as an advocate of climate policies, and encourages communication of the health impacts of climate change when counseling patients. Our aim is to inspire the reader to invest more time in communicating the most crucial public health issue of the 21st century to their patients.

Point-of-Care Saliva Osmolarity Testing for the Screening of Hydration in Older Adults With Hypertension

OBJECTIVES

Older adults have an elevated risk of dehydration, a state with proven detrimental cognitive and physical effects. Furthermore, the use of diuretics by hypertensive patients further compounds this risk. This prospective study investigated the diagnostic accuracy of point-of-care (POC) salivary osmolarity (SOSM) measurement for the detection of dehydration in hypertensive adults with and without diuretic pharmacotherapy.

DESIGN

Prospective diagnostic accuracy study.

SETTING

Home visits to patients recruited from 4 community health centers in West Sulawesi, Indonesia.

PARTICIPANTS

A total of 148 hypertensive older adults (57 men, 91 women). The mean ages of male and female patients were 69.4 ± 11.4 and 68.1 ± 7.8 years, respectively.

METHODS

Hypertensive adults were divided into 2 groups based on the presence of diuretics in their pharmacotherapeutic regimen. First-morning mid-stream urine samples were used to perform urine specific gravity (USG) testing. Same-day SOSM measurements were obtained using a POC saliva testing system.

RESULTS

Both USG (P = .0002) and SOSM (P < .0001) were significantly elevated in hypertensive patients with diuretic pharmacotherapy. At a USG threshold of ≥1.030, 86% of diuretic users were classified as dehydrated compared with 55% of non-using participants. A strong correlation was observed between USG and SOSM measurements (r = 0.78, P < .0001). Using a USG threshold of ≥1.030 as a hydration classifier, an SOSM threshold of ≥93 mOsm had a sensitivity of 78.6% and a specificity of 91.1% for detecting dehydration.

CONCLUSIONS AND IMPLICATIONS

Hypertensive patients on diuretics have significantly higher first-morning USG and SOSM values, indicating a higher likelihood of dehydration relative to those on other classes of antihypertensive medication. POC SOSM assessment correlates strongly with first-morning USG assessment, and represents a rapid and noninvasive alternative to urinary hydration assessment that may be applicable for routine use in populations with elevated risk of dehydration.

Triggering of myocardial infarction by heat exposure is modified by medication intake

Acute myocardial infarction (MI) can be triggered by heat exposure, but it remains unknown whether patients taking certain cardiovascular medications have elevated vulnerability. Based on a validated and complete registration of all 2,494 MI cases in Augsburg, Germany, during warm seasons (May to September) from 2001 to 2014, here we show that heat-related non-fatal MI risk was elevated among users of anti-platelet medication and beta-receptor blockers, respectively, but not among non-users, with significant differences between users and non-users. We also found that these effect modifications were stronger among younger patients (25-59 years), who had a lower prevalence of pre-existing coronary heart disease (CHD, a potential confounder by indication), than among older patients (60-74 years), who had a higher prevalence of pre-existing CHD. Users of these medications may be more vulnerable than non-users to non-fatal MI risk due to heat exposure. Further research is needed to disentangle effect modification by medication use from effect modification by pre-existing CHD.

Mortality risk related to heatwaves in Finland - Factors affecting vulnerability

BACKGROUND

Heatwaves are known to increase mortality. However, there is a need for more quantitative information on factors affecting sensitivity to the adverse health effects, particularly in countries with cool summer temperatures.

OBJECTIVES

We evaluated mortality risk related to heatwave days in Finland. Risk was examined by age, sex, cause of death, and place of death, including health and social care facilities and homes. Mortality was also analysed for different patient subgroups in healthcare facilities.

METHODS

Heatwaves were defined as periods when the daily average temperature exceeded the 90th percentile of that from May to August in 2000-2014 for ≥4 days. In addition to all heatwave days, risk was analysed for short (4-5 days) and long (≥10 days) heatwaves. Mortality analyses were based on linking registry data on i) daily non-accidental and cause-specific mortality and ii) admissions to a health or social care facility. Statistical analyses were conducted using generalised estimating equations for longitudinal data analysis, assuming a Poisson distribution for the daily mortality count.

RESULTS

During all heatwave days, mortality increased among those aged 65-74 years (6.7%, 95% confidence interval 2.9-10.8%) and ≥75 years (12.8%, 95% CI 9.8-15.9%). Mortality increased in both sexes, but the risk was higher in women. Positive associations were observed for deaths due to respiratory diseases, renal diseases, mental and behavioural disorders, diseases of the nervous system, and cardiovascular diseases. Overall, effects were stronger for long than short heatwaves. During all heatwave days, mortality increased in healthcare facilities in outpatients (26.9%, 95% CI 17.3-37.2%) and inpatients. Among inpatients, the risk was higher in long-term inpatients (stay in ward > 30 days, 13.1%, 95% CI 8.6-17.7%) than others (5.8%, 95% CI 2.7-9.0%). At homes, mortality increased by 8.1% (95% CI 1.9-14.6%). Elevated risk estimates were also detected for social care facilities.

CONCLUSIONS

In Finland, a cold-climate Northern country, heatwaves increase mortality risk significantly among the elderly. Women are more susceptible than men, and many chronic diseases are important risk factors. To reduce heatwave-related deaths, preparedness should be improved particularly in hospital and healthcare centre wards, where the most vulnerable are long-term inpatients. However, measures are also needed to protect the elderly at home and in social care facilities, especially during prolonged hot periods.

Geospatial indicators of exposure, sensitivity, and adaptive capacity to assess neighbourhood variation in vulnerability to climate change-related health hazards

BACKGROUND

Although the frequency and magnitude of climate change-related health hazards (CCRHHs) are likely to increase, the population vulnerabilities and corresponding health impacts are dependent on a community's exposures, pre-existing sensitivities, and adaptive capacities in response to a hazard's impact. To evaluate spatial variability in relative vulnerability, we: 1) identified climate change-related risk factors at the dissemination area level; 2) created actionable health vulnerability index scores to map community risks to extreme heat, flooding, wildfire smoke, and ground-level ozone; and 3) spatially evaluated vulnerability patterns and priority areas of action to address inequity.

METHODS

A systematic literature review was conducted to identify the determinants of health hazards among populations impacted by CCRHHs. Identified determinants were then grouped into categories of exposure, sensitivity, and adaptive capacity and aligned with available data. Data were aggregated to 4188 Census dissemination areas within two health authorities in British Columbia, Canada. A two-step principal component analysis (PCA) was then used to select and weight variables for each relative vulnerability score. In addition to an overall vulnerability score, exposure, adaptive capacity, and sensitivity sub-scores were computed for each hazard. Scores were then categorised into quintiles and mapped.

RESULTS

Two hundred eighty-one epidemiological papers met the study criteria and were used to identify 36 determinant indicators that were operationalized across all hazards. For each hazard, 3 to 5 principal components explaining 72 to 94% of the total variance were retained. Sensitivity was weighted much higher for extreme heat, wildfire smoke and ground-level ozone, and adaptive capacity was highly weighted for flooding vulnerability. There was overall varied contribution of adaptive capacity (16-49%) across all hazards. Distinct spatial patterns were observed - for example, although patterns varied by hazard, vulnerability was generally higher in more deprived and more outlying neighbourhoods of the study region.

CONCLUSIONS

The creation of hazard and category-specific vulnerability indices (exposure, adaptive capacity and sensitivity sub-scores) supports evidence-based approaches to prioritize public health responses to climate-related hazards and to reduce inequity by assessing relative differences in vulnerability along with absolute impacts. Future studies can build upon this methodology to further understand the spatial variation in vulnerability and to identify and prioritise actionable areas for adaptation.

Heatwaves, medications, and heat-related hospitalization in older Medicare beneficiaries with chronic conditions

Background

Heatwaves kill more people than floods, tornadoes, and earthquakes combined and disproportionally affect older persons and those with chronic conditions. Commonly used medications for chronic conditions, e.g., diuretics, antipsychotics disrupt thermoregulation or fluid/electrolyte balance and may sensitive patients to heat. However, the effect of heat-sensitizing medications and their interactions with heatwaves are not well-quantified. We evaluated effects of potentially heat-sensitizing medications in vulnerable older patients.

Methods

US Medicare data were linked at the zip code level to climate data with surface air temperatures for June-August of 2007–2012. Patients were Medicare beneficiaries aged ≥65 years with chronic conditions including diabetes, dementia, and cardiovascular, lung, or kidney disease. Exposures were potentially heat-sensitizing medications including diuretics, anticholinergics, antipsychotics, beta blockers, stimulants, and anti-hypertensives. A heatwave was defined as ≥2 days above the 95^th percentile of historical zip code-specific surface air temperatures. We estimated associations of heat-sensitizing medications and heatwaves with heat-related hospitalization using self-controlled case series analysis.

Results

We identified 9,721 patients with at least one chronic condition and heat-related hospitalization; 42.1% of these patients experienced a heatwave. Heatwaves were associated with an increase in heat-related hospitalizations ranging from 21% (95% CI: 7% to 38%) to 33% (95% CI: 14% to 55%) across medication classes. Several drug classes were associated with moderately elevated risk of heat-related hospitalization in the absence of heatwaves, with rate ratios ranging from 1.16 (95% CI: 1.00 to 1.35) to 1.37 (95% CI: 1.14 to 1.66). We did not observe meaningful synergistic interactions between heatwaves and medications.

Conclusions

Older patients with chronic conditions may be at heightened risk for heat-related hospitalization due to the use of heat-sensitizing medications throughout the summer months, even in the absence of heatwaves. Further studies are needed to confirm these findings and also to understand the effect of milder and shorter heat exposure.

Global warming, heat-related illnesses, and the dermatologist

Global warming, provoked by the greenhouse effect of high levels of atmospheric gases (most notably carbon dioxide and methane), directly threatens human health and survival. Individuals vary in their capacity to tolerate episodes of extreme heat. Because skin is the organ tasked with heat dissipation, it is important for dermatologists to be versed in the physiology of cutaneous heat dissipation and cognizant of clinical settings in which the skin’s thermoregulatory responses may be impaired. When the external temperature is lower than that of the skin, the skin releases internal heat through direct thermal exchange with the environment, a process that is aided by an expansion of cutaneous blood flow and eccrine sweating. Cooling through the evaporation of sweat is effective even when the external temperature exceeds that of skin. Many factors, including environmental and physiological (e.g., age and sex), and pathological (e.g., preexisting illnesses, disorders of eccrine function, and medications) considerations, affect the skin’s capacity to thermoregulate. Identification of individuals at increased risk for heat-related morbidity and mortality will become increasingly important in the care of patients.

Drug-associated hyperthermia: A longitudinal analysis of hospital presentations

WHAT IS KNOWN AND OBJECTIVE

Hyperthermia occurs when heat accumulation surpasses the body's ability for heat dissipation. Many drugs can affect thermoregulation through mechanisms including altering the neurotransmitters that cause increased heat production or decreased heat loss and may, therefore, be associated with hyperthermia. This study aimed to examine hospitalizations and emergency department (ED) presentations due to hyperthermia and to investigate the potential association with drug therapy.

METHODS

A retrospective analysis of ED presentations and hospitalizations due to hyperthermia in all four major hospitals in Tasmania, Australia, between July 2010 and December 2018 was performed. Data of patients aged ≥18 years were extracted from the hospital digital medical records and analysed for the prevalence, trends and various potential risk factors for hyperthermia, such as age, environmental temperature and drug therapy.

RESULTS

This study included 224 patients. The data illustrated a trend with time, albeit not statistically significant, towards increasing hospital presentations due to hyperthermia. Antiepileptics (P = .03) and furosemide (P = .04) were the most frequently used drugs in patients with primary hyperthermia. The high use of levothyroxine in the study population (6.7%) stood out compared with the estimated national average (2.1%). Various drug classes associated with hyperthermia were used significantly more in the age group ≥60 years, suggesting polypharmacy in the elderly as a contributing factor for hyperthermia.

WHAT IS NEW AND CONCLUSION

This study reports a possible association of some drugs, particularly diuretics (furosemide), antiepileptics and levothyroxine, with hyperthermia. Healthcare professionals should be aware of the increasing prevalence of hyperthermia and the possible involvement of drugs.

Drug-associated non-pyrogenic hyperthermia: a narrative review

PURPOSE

Hyperthermia occurs when heat accumulation surpasses the body's ability for heat dissipation. Many drugs may affect thermoregulation. This narrative review aimed to provide an overview of the current literature concerning reports of drug-associated non-pyrogenic hyperthermia.

METHODS

A comprehensive search was performed across 5 databases covering the period of inception to March 2019, for publications that reported hyperthermia associated with drug use. Studies that reported potential drug association with hyperthermia due to altered thermoregulatory mechanisms were included. Case reports of less than 3 cases were excluded, as well as hyperthermia due to other causes, such as hypersensitivity, malignant hyperthermia and neuroleptic malignant syndrome. The primary outcomes of interest were hospitalisation and mortality.

RESULTS

The literature search initially identified a total of 2609 records. Based on full-text analysis, 11 articles met the inclusion criteria, of which there were 5 case-control studies, 2 case series and 4 retrospective analyses. Studies reported heat-related hospitalisations or emergency department presentations associated with the use of psychotropics (antipsychotics, antidepressants and anxiolytics), anticholinergics, antihistamines, diuretics, cardiovascular agents, non-steroidal anti-inflammatory drugs and anticoagulants. Psychotropic drugs were reported to be associated with increased heat-related mortality, other than through neuroleptic malignant syndrome, but findings varied among the studies.

CONCLUSION

Given the relative lack of publications, more research is necessary to study specific effects of drugs on body temperature and the likelihood of inducing non-pyrogenic hyperthermia. In particular, psychotropics, anticholinergics, diuretics and cardiovascular agents are of interest for future studies.

Effects of Drugs and Excipients on Hydration Status

Despite being the most essential nutrient, water is commonly forgotten in the fields of pharmacy and nutrition. Hydration status is determined by water balance (the difference between water input and output). Hypohydration or negative water balance is affected by numerous factors, either internal (i.e., a lack of thirst sensation) or external (e.g., polypharmacy or chronic consumption of certain drugs). However, to date, research on the interaction between hydration status and drugs/excipients has been scarce. Drugs may trigger the appearance of hypohydration by means of the increase of water elimination through either diarrhea, urine or sweat; a decrease in thirst sensation or appetite; or the alteration of central thermoregulation. On the other hand, pharmaceutical excipients induce alterations in hydration status by decreasing the gastrointestinal transit time or increasing the gastrointestinal tract rate or intestinal permeability. In the present review, we evaluate studies that focus on the effects of drugs/excipients on hydration status. These studies support the aim of monitoring the hydration status in patients, mainly in those population segments with a higher risk, to avoid complications and associated pathologies, which are key axes in both pharmaceutical care and the field of nutrition.

Timing and Predictors of Mild and Severe Heat Illness among New Military Enlistees

PURPOSE

Heat illnesses are important and potentially fatal conditions among physically active individuals. We determined predictors of heat illness among enlistees in a large military population experiencing common physical activity patterns.

METHODS

We estimated the adjusted odds of mild (MHI) and severe (SHI) heat illness associated with demographic, health-related, and geographic factors among active-duty, US Army soldiers enlisting between January 2011 and December 2014 (N = 238,168) using discrete-time multivariable logistic regression analyses.

RESULTS

We observed 2612 incident cases of MHI and 732 incident cases of SHI during 427,922 person-years of follow-up, with a mean and median of 21.6 and 21 months per subject. During the first 6 duty months, 71.3% of the MHIs and 60.2% of the SHIs occurred, peaking at month 2. The odds of MHI quadrupled among those with prior SHI (odds ratio [OR], 4.02; 95% confidence interval [CI], 2.67-6.03). Body mass index (BMI) extremes increased the odds substantially (OR at BMI ≥30 kg·m: for MHI, 1.41 (CI, 1.19-1.67); for SHI, 1.94 (CI, 1.47-2.56); OR at BMI <18.5 kg·m: for MHI, 1.50 (CI, 1.01-2.21); for SHI, 2.26 (CI, 1.16-4.39)). Tobacco use was associated with a 55% increase (CI, 1.37-1.77) in MHI odds. The odds of MHI increased if taking nonsteroidal anti-inflammatory drugs, opioids, or methylphenidate stimulants. Lower age and lower entry aptitude scores were associated with progressively increased MHI odds.

CONCLUSIONS

Most heat illnesses occurred at the outset of service, indicating the need for focused prevention methods at the initiation of military duty. Prior heat illness, BMI extremes, medications, and tobacco use represent potentially actionable risk factors to address by education, policy, and/or clinician intervention.

Magnesium and mood disorders: systematic review and meta-analysis

BACKGROUND

Magnesium (Mg2+) has received considerable attention with regards to its potential role in the pathophysiology of the mood disorders, but the available evidence seems inconclusive.AimsTo review and quantitatively summarise the human literature on Mg2+ intake and Mg2+ blood levels in the mood disorders and the effects of Mg2+ supplements on mood.

METHOD

Systematic review and meta-analyses.

RESULTS

Adherence to a Mg2+-rich diet was negatively associated with depression in cross-sectional (odds ratio = 0.66) but not in prospective studies. Mg2+ levels in bodily fluids were on average higher in patients with a mood disorder (Hedge's g = 0.19), but only in patients treated with antidepressants and/or mood stabilisers. There was no evident association between Mg2+ levels and symptom severity. Mg2+ supplementation was associated with a decline in depressive symptoms in uncontrolled (g = -1.60) but not in placebo-controlled trials (g = -0.21).

CONCLUSION

Our results provide little evidence for the involvement of Mg2+ in the mood disorders.Declaration of interestNone.