Early hypophosphataemia and refeeding syndrome in extremely low birthweight babies and outcomes to 2 years of age: secondary cohort analysis from the ProVIDe trial

OBJECTIVE

To investigate in extremely low birthweight (ELBW; <1000 g) babies the associations between refeeding syndrome (serum phosphate <1.4 mmol·L-1 and serum total calcium>2.8 mmol·L-1) and hypophosphataemia in the first week and death or neurodisability at 2 years' corrected age (CA).

DESIGN

Secondary cohort analysis of the ProVIDe trial participants with serum biochemistry within 7 days of birth. At 2 years' CA, neurodisability was assessed by Bayley Scales of Infant Development Edition III and neurological examination. Associations between neurodisability and other variables were analysed using t-tests and logistic regression adjusted for sex and smallness-for-gestational age.

SETTING

Six tertiary neonatal intensive care units (NICUs) in New Zealand.

PARTICIPANTS

352 ELBW babies born between 29 April 2014 and 30 October 2018.

MAIN OUTCOME MEASURE

Death or neurodisability at 2 years' CA.

RESULTS

Fifty-nine babies died, two after discharge from the NICU. Of the 336 babies who survived to 2 years' CA, 277 had neurodevelopmental assessment and 107 (39%) had a neurodisability. Death or neurodisability was more likely in babies who had refeeding syndrome (aOR 1.96 (95% CI 1.09 to 3.53), p=0.02) and in babies who had hypophosphataemia (aOR 1.74 (95% CI 1.09 to 2.79), p=0.02). Hypophosphataemia was associated with increased risk of death (aOR 2.07 (95% CI 1.09 to 3.95), p=0.03)) and severe hypophosphataemia (<0.9 mmol·L-1) with increased risk of death (aOR 2.67 (95% CI 1.41 to 5.00), p=0.002) and neurodisability (aOR 2.31 (95% CI 1.22 to 4.35), p=0.01).

CONCLUSIONS

In ELBW babies, refeeding syndrome and hypophosphataemia in the first week are associated with death or neurodisability. Until optimal phosphate requirements are determined through further research, monitoring for hypophosphataemia and mitigation strategies are indicated.

TRIAL REGISTRATION NUMBER

ACTRN12612001084875.

Sodium Glycerophosphate vs. Inorganic Phosphate Use in Parenteral Nutrition for Preterm Infants: A Retrospective Study

BACKGROUND/OBJECTIVES

Sodium glycerophosphate improves the adverse side effects of parenteral nutrition. Therefore, this study aimed to evaluate different outcomes, including metabolic bone disease and electrolyte imbalance, associated with the use of sodium glycerophosphate or inorganic phosphate in parenteral nutrition for preterm neonates.

METHODS

This retrospective cohort study enrolled 402 newborns admitted to the neonatal intensive care unit of one medical center between January 2019 and September 2021. Of them, 205 received sodium glycerophosphate as parenteral nutrition, while the other 197 received inorganic phosphate. Baseline characteristics and growth parameters, including body weight, body length, and head circumference in the first year of life; calcium and phosphate content of parenteral nutrition in the first 4 weeks; calcium, phosphorus, alkaline phosphatase (ALP), and creatinine levels; and morbidities were compared.

RESULTS

During the first 4 weeks, the calcium and phosphate contents of parenteral nutrition were significantly higher in the sodium glycerophosphate vs. inorganic phosphate group. Growth parameters did not differ significantly between groups. The sodium glycerophosphate group showed a higher mean serum phosphate level (4.0 ± 1.2 mg/dL vs. 3.5 ± 1.3 mg/dL, p = 0.001), lower serum ALP level (402.8 ± 202.8 U/L vs. 466.4 ± 228.6 U/L, p = 0.004), lower seizure incidence (4.9% vs. 13.2%, p = 0.003), and higher hypocalcemia incidence (41.5% vs. 31.5%, p = 0.038). However, there were no significant intergroup differences in other common morbidities such as metabolic bone diseases of prematurity, bronchopulmonary dysplasia, electrolyte imbalance, hypoglycemia, retinopathy of prematurity, or intraventricular hemorrhage.

CONCLUSIONS

Compared to inorganic phosphate, sodium glycerophosphate is associated with higher serum phosphate levels, lower ALP levels, and reduced seizure incidence in premature infants. However, as the study was retrospective and single-center, further randomized controlled trials are needed to confirm these findings.

Association of Hypophosphatemia during Continuous Kidney Replacement Therapy and Clinical Outcomes: A Systematic Review and Meta-Analysis

INTRODUCTION

Hypophosphatemia is a common and potentially severe complication of continuous kidney replacement therapy (CKRT), but the evidence on the correlation between hypophosphatemia occurring during CKRT and clinical outcomes remains limited.

METHODS

Electronic databases (PubMed, Embase, Web of Science, and the Cochrane database) were searched from inception to March 1, 2024. All possible studies that examined the following outcomes were included: all-cause mortality, mechanical ventilation, intensive care unit (ICU) stay, and CKRT duration.

RESULTS

A total of 8,631 patients from eight cohort studies were included. There was no statistical association between hypophosphatemia during CKRT and all-cause mortality in critically ill patients (OR 0.82, 95% CI 0.57-1.18, p = 0.28, I2 = 83%). However, hypophosphatemia was associated with longer duration of mechanical ventilation (WMD 80.30 h, 95% CI 31.37-129.22, p = 0.001, I2 = 60%). Furthermore, a longer length of ICU stay (WMD 2.76 d, 95% CI 2.50-3.02, p < 0.00001, I2 = 36%) and CKRT duration (WMD 51.51 h, 95% CI 2.69-100.34, p = 0.04, I2 = 96%) were observed in patients with hypophosphatemia.

CONCLUSIONS

The association between hypophosphatemia and mortality in patients receiving CKRT was insufficient. However, hypophosphatemia during CKRT might be associated with adverse clinical outcomes for critically ill patients.

The association between serum phosphate and length of hospital stay and all-cause mortality in adult patients: a cross-sectional study

BACKGROUND

Data is limited on the prevalence of hypophosphatemia in general hospitalized patients, and its association with length of hospital stay (LOS) and mortality remained unclear. We aimed to investigate the prevalence of admission phosphate abnormality and the association between serum phosphate level and length of hospital stay and all-cause mortality in adult patients.

METHODS

This was a multi-center retrospective study based on real-world data. Participants were classified into five groups according to serum phosphate level (inorganic phosphorus, iP) within 48 h after admission: G1, iP < 0.64 mmol/L; G2, iP 0.64-0.8 mmol/L; G3, iP 0.8-1.16 mmol/L; G4, iP 1.16-1.45 mmol/L; and G5, iP ≥ 1.45 mmol/L, respectively. Both LOS and in-hospital mortality were considered as outcomes. Clinical information, including age, sex, primary diagnosis, co-morbidity, and phosphate-metabolism related parameters, were also abstracted from medical records.

RESULTS

A total number of 23,479 adult patients (14,073 males and 9,406 females, aged 57.7 ± 16.8 y) were included in the study. The prevalence of hypophosphatemia was 4.74%. An "L-shaped" non-linear association was determined between serum phosphate level and LOS and the inflection point was 1.16 mmol/L in serum phosphate level. Compared with patients in G4, patients in G1, G2 or G3 were significantly associated with longer LOS after full adjustment of covariates. Each 0.1 mmol/L decrease in serum phosphate level to the left side of the inflection point led to 0.64 days increase in LOS [95% confidence interval (CI): 0.46, 0.81; p for trend < 0.001]. But there was no association between serum phosphate and LOS where serum levels of phosphate ≥ 1.16 mmol/L. Multivariable logistic regression analysis showed that adjusted all-cause in-hospital mortality was 3.08-fold greater in patients in G1 than those in G4 (95% CI: 1.52, 6.25; p for trend = 0.001). Similarly, no significant association with either LOS or mortality were found in patients in G5, comparing with G4.

CONCLUSIONS

Hypophosphatemia, but not hyperphosphatemia, was associated with LOS and all-cause mortality in adult inpatients. It is meaningful to monitor serum levels of phosphate to facilitate early diagnosis and intervention.

Serum 25-Hydroxyvitamin D Level Is Negatively Associated with Fatigue in Elderly Maintenance Hemodialysis Patients

INTRODUCTION

Chronic kidney disease-mineral and bone disorder (CKD-MBD) is frequently observed in maintenance hemodialysis (MHD) patients and is associated with fracture, muscle weakness, malnutrition, etc.; however, relationships of CKD-MBD markers and fatigue are not well established.

METHODS

This was a cross-sectional study including 244 MHD patients (89 elders) from July to September 2021 in the First Affiliated Hospital of Shandong First Medical University. CKD-MBD markers and other clinical data were collected from medical records. Fatigue in the past week was measured by Standardized Outcomes in Nephrology-Hemodialysis (SONG-HD) fatigue measure; fatigue at the end of hemodialysis was measured by numeric rating scale (NRS). Spearman correlation, linear regression, and robust linear regression were.

RESULTS

In all MHD patients, lg[25(OH)D] (nmol/L) was negatively correlated with SONG-HD score (β = -1.503, 95% CI: -2.826 to 0.18, p = 0.026) and NRS score (β = -1.532, p = 0.04) in multiple regression models adjusting for sex, age, and all CKD-MBD characters; but no correlations were found on univariate regression or in other multiple regression models. Interaction effects between age ≥65 years and lg(25[OH]D [nmol/L]) in terms of fatigue scores were significant based on multiple linear regressions (SONG-HD score β = -3.613, p for interaction = 0.006; NRS score β = -3.943, p for interaction = 0.008). Compared with non-elderly patients, elderly patients were with higher ACCI scores (7 [6, 8] vs. 4 [3, 5], p < 0.001), higher SONG-HD scores (3 [2, 6] vs. 2 [1, 3], p < 0.001), higher NRS score (4 [2, 7] vs. 3 [1, 5], p < 0.001), lower serum phosphate levels (1.65 [1.29, 2.10] vs. 1.87 [1.55, 2.26] mmol/L, p = 0.002), and lower serum iPTH levels (160.6 [90.46, 306.45] vs. 282.2 [139, 445.7] pg/mL, p < 0.001). There were no differences in serum calcium, alkaline serum, or 25(OH)D levels between the two groups. In elderly patients, lg[25(OH)D] was negatively correlated with SONG-HD score (β = -3.323, p = 0.010) and NRS score (β = -3.521, p = 0.006) on univariate linear regressions. Following adjustment for sex, age, and all CKD-MBD characters, lg[25(OH)D] was negatively correlated with SONG-HD scores (multiple linear regression β = -4.012, p = 0.004; multiple robust regression β = -4.012, p = 0.003) or NRS scores (multiple linear regression β = -4.104, p = 0.002; multiple robust regression β = -4.104, p = 0.001). There were no significant correlations between fatigue scores and other CKD-MBD markers (calcium, phosphate, lgiPTH, alkaline phosphatase) in elderly MHD patients, on either univariate linear regressions or multiple regressions.

CONCLUSION

Serum 25(OH)D level is negatively associated with fatigue in elderly MHD patients.

Potential Therapeutic Properties of the Leaf of Cydonia Oblonga Mill. Based on Mineral and Organic Profiles

Leaf extract of Cydonia Oblonga Mill. is interesting for further exploration of the potential of its substrates for therapeutic supplements. Quantitative and qualitative analyses were conducted on samples of green (October), yellow (November), and brown (December) quince leaves collected in the region of Pinhel, Portugal. Mineral analysis determined the measurements of the levels of several macro- and micro-elements. Organic analysis assessed the moisture content, total phenolic content (TPC), vitamin E, and fatty acid (FA) profiles. Mineral analysis was based on ICP-MS techniques, while the profiles of vitamin E and FA relied on HPLC-DAD-FLD and GC-FID techniques, respectively. Moisture content was determined through infrared hygrometry and TPC was determined by spectrophotometric methods. Regarding the mineral content, calcium, magnesium, and iron were the most abundant minerals. Concerning organic analysis, all leaf samples showed similar moisture content, while the TPC of gallic acid equivalents (GAE) and total vitamin E content, the most predominant of which was the α-tocopherol isomer, showed significant variations between green-brown and yellow leaves. FA composition in all leaf samples exhibited higher contents of SFA and PUFA than MUFA, with a predominance of palmitic and linolenic acids. Organic and inorganic analysis of quince leaves allow for the prediction of adequate physiological properties, mainly cardiovascular, pulmonary, and immunological defenses, which with our preliminary in silico studies suggest an excellent supplement to complementary therapy, including drastic pandemic situations.

Association Between Admission Serum Phosphate Level and All-Cause Mortality Among Patients with Spontaneous Intracerebral Hemorrhage

Background

Hypophosphatemia was reported to frequently occur in patients with nontraumatic intracranial hemorrhage (ICH); however, the correlation between hypophosphatemia and outcomes of ICH remains unclear. This study aimed to examine the association between admission serum phosphate and all-cause mortality among patients with mild–moderate spontaneous ICH (sICH).

Methods

A total of 851 patients with sICH were enrolled. Serum phosphate was acquired within 24 hours on admission, and participants were divided according to phosphate quartiles. The primary outcome was all-cause mortality within 90 days, and univariate and multivariate models were employed to estimate the mortality risk.

Results

There were significant differences among sICH patients with different phosphate quartiles in terms of age, diastolic blood pressure (DBP), activated partial thromboplastin time (APTT), platelet count, and incidence of respiratory failure events on admission (P < 0.05). Log rank test showed a significant difference in the mortality risk among sICH patients with each phosphate quartile. Univariate Cox regression analysis revealed that age, smoking, DBP, APTT, NIH stroke scale (NIHSS) score, hematoma volume and serum phosphate might be associated with the 90-day all-cause mortality in patients with sICH (P < 0.05). Multivariable Cox regression analysis showed that the crude mortality was 4.3-fold greater in sICH patients with serum phosphate Q1 than those with Q4 (P < 0.001), and remained 3.18-fold higher after adjusting for age, smoking, DBP, APTT, NIHSS score, hematoma volume and early withdrawal of life-sustaining therapy (P = 0.011). Representative operating curve (ROC) analysis showed that admission serum phosphate was predictable for all-cause mortality within 90 days in patients with sICH (area under the ROC = 0.628, P < 0.001).

Conclusion

Low admission serum phosphate is strongly associated with a high risk of mortality in patients with mild–moderate sICH, and hypophosphatemia may be a prognostic marker for all-cause mortality in patients with mild–moderate sICH.

Hypophosphatemia in critically ill pediatric patients receiving enteral and oral nutrition

BACKGROUND

Hypophosphatemia(HP) is related to several comorbidities in pediatric intensive care units (PICUs). This study aimed to evaluate the incidence of HP in severely ill pediatric patients receiving oral and/or enteral nutrition. The secondary objectives were to investigate the association between HP and the inflammatory state, PICU length of stay, severity, mortality, nutrition status, and protein, energy, calcium, vitamin D, and phosphate intake.

METHODS

A prospective, observational cohort study was conducted in a PICU of a quaternary hospital. Participants aged between 28 days and 14 years were included. Anthropometric and laboratory assessments were performed ≤72 h after PICU admission and repeated after 7 days for three consecutive times. Energy, protein, calcium, phosphate, and vitamin D intake per day of hospitalization were recorded individually. The Pediatric Index of Mortality 2 (PIM2) was used to determine each patient's severity score.

RESULTS

A total of 103 participants were included in the study. Hypophosphatemic events ranged from 27.2% to 37.5% among the assessments. HP was associated with high C-reactive protein levels (P = .012) and lower energy adequacy (P = .037). Serum phosphorus was inversely correlated (weak correlation) with PIM2 (P = .017).

CONCLUSION

HP is common in critically ill pediatric patients, even when they are not receiving parenteral nutrition. It is necessary to monitor serum phosphorus levels and consider the possibility of early replacement, especially in patients showing high levels of inflammation. In addition to inflammation itself, low energy intake and illness severity were related to HP.

Does a rise in plasma erythropoietin after high-altitude exposure affect FGF23 in healthy volunteers on a normal or low-phosphorus diet?

BACKGROUND AND AIMS

Data of experimental rodent models suggest that hypoxia with subsequent increase in erythropoietin stimulates the expression of the phosphaturic hormone fibroblast growth factor 23 (FGF23).

METHODS AND RESULTS

To translate the findings of animal studies into human physiology, herein we exposed eight healthy volunteers to high altitude (2656 m above sea level) for four days. The volunteers were randomized on a low-phosphorous diet (n = 4) or a normal phosphorus diet (n = 4). Although high-altitude exposure caused a significant increase in plasma erythropoietin (EPO) (before high-altitude exposure: low phosphorus: median EPO 6.6 mIU/ml [interquartile range (IQR) 6.0; 8.2], normal phosphorus: median EPO 9.0 mIU/ml [IQR 7.9; 11.5]; at day 2: low phosphorus: median EPO 21.3 mIU/ml [IQR 19.5; 23.8], normal phosphorus: median EPO 19.4 mIU/ml [IQR 18.0; 20.8]), there was no consistent increase in plasma c-terminal FGF23 or plasma intact FGF23. We observed only a single, intermittent peak in c-terminal FGF23 levels after 5 h of maximal aerobic exercise.

CONCLUSION

These data do not support a substantial effect of moderate hypoxia alone on the expression of FGF23, but they suggest that combined exercise and high-altitude exposure may temporarily induce FGF23 expression.

Low serum phosphate and magnesium levels are associated with peripheral neuropathy in patients with type 2 diabetes mellitus

AIMS

To determine the relationship of serum phosphate, serum magnesium and peripheral nerve function in patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 254 patients diagnosed with T2DM were included. Peripheral nerve function was evaluated by nerve conduction study with the use of electromyography. Composite z scores of conduction velocity, latency, and amplitude were constructed, respectively. Demographic, medical and laboratory data including serum phosphate and magnesium were collected.

RESULTS

Serum phosphate and serum magnesium levels were significantly lower in patients with diabetic peripheral neuropathy (DPN) (P < 0.01). And the percentages of DPN patients were lower in high tertile of serum phosphate and serum magnesium (P < 0.05). Furthermore, composite z score of conduction velocity (CV) (P = 0.012) were positively associated with serum phosphate levels and the composite z score of amplitude (P < 0.001) and CV (P = 0.041) were positively associated with serum magnesium levels. After adjusting potential related factors (age, gender, smoking, diabetes duration, body mass index, systolic blood pressure, glycated hemoglobin, total cholesterol, estimated glomerular filtration rate), serum levels of phosphate and magnesium were still related to status of DPN in logistic regression (P < 0.05).

CONCLUSION

Lower serum phosphate and magnesium significantly correlated with parameters of nerve conduction in T2DM patients. Serum phosphate and magnesium might underlie the pathophysiologic features of DPN.

[Causes, consequences and treatment of hypophosphatemia: A systematic review]

CONTEXT

Although hypophosphatemia is usually very seldom, it can reach two to 3% of hospitalized patients and until 28% of intensive care unit patients. Due to the lack of knowledge, clinical practice regarding seeking or treatment of hypophosphatemia is very heterogenous. However its clinical consequences might be heavy. A better knowledge of its causes, physiopathological effects and treatment should lead to a documented and homogenous care of these patients in clinics.

OBJECTIVE

The aim of our study was a systematic review of littérature, seeking for publications about causes, consequences and treatment of hypophosphatemia.

DOCUMENTARY SOURCES (KEYWORDS AND LANGUAGE)

A research has been conducted on the Medline database by using the following keywords "phosphorus supplementation", "hypophosphatemia" and ("physiopathology" or "complications").

RESULTS

Three mains mechanisms might be responsible for hypophosphatemia: a decrease in digestive absorption, a rise in kidney excretion and a transfer of phosphorus to the intracellular compartment. Denutrition, acid base balance troubles, parenteral nutrition or several drugs are capable of provoking or favouring hypophosphatemia. All these situations are frequently encountered in intensive care unit. Consequences of hypophosphatemia might be serious. Best studied and documented are cardiac and respiratory muscle contractility decrease, sometimes leading to acute cardiac and respiratory failure, cardiac rhythm troubles and cardiac arrest. Hypophosphatemia is frequent during sepsis. It could be responsible for leucocyte dysfunction that might favour or increase sepsis. The treatment of hypophosphatemia is usually simple through a supplementation that quickly restores a regular concentration, with few adverse effects when regularly used.

CONCLUSION

During at-risk situations, the systematic search for hypophosphatemia and its treatment may limit the occurrence of serious consequences.

Long-term adefovir therapy may induce Fanconi syndrome: A report of four cases

Fanconi syndrome is a rare disease characterized by dysfunction of the proximal renal tubules as a result of various pathogenic events. Drug-induced Fanconi syndrome may be neglected or misdiagnosed, which increases the level of suffering. The aim of the present study was to conduct an investigation into the effects of adefovir (ADV)-induced Fanconi syndrome. Four typical cases of Fanconi syndrome caused by long-term ADV therapy (2-9 years) were diagnosed at our hospital. A complete medical and therapy history was collected from all four patients prior to a physical examination. Laboratory and diagnostic examinations were also conducted. Following this, the patients were diagnosed and a treatment regimen was decided upon. Outcomes of the treatment regimen were observed. Common manifestations of all the four patients were: Renal tubular reabsorption dysfunction; imbalanced electrolyte acid-base ratio; elevated cystatin C levels; severe hypophosphatemia and diffused systemic pain; osteoporosis; and difficultly walking. When ADV was replaced with supportive treatment, all the four patients exhibited symptom relief. These findings indicate that long-term ADV therapy may induce Fanconi syndrome. For patients with a history of such therapy, the possibility of Fanconi syndrome should be assessed and monitored closely for indicators, including altered glomerular and renal tubular function. Once diagnosed, the agent should be immediately discontinued and prompt symptomatic treatment should be administered.

Covariation between plasma phosphate and daytime cortisol in early Parkinson's disease

BACKGROUND

Disturbed phosphate homeostasis in early Parkinson's disease (PD) may originate from a stress-related condition and nutritional status among other risk factors, age, and gender.

METHODS

Risk of malnutrition using Mini-nutritional assessment (MNA score) and plasma levels of protein markers and daytime cortisol at the time of diagnosis in PD (n = 75) were compared with a control group (n = 24). Cognition was assessed using the Mini-Mental State Examination (MMSE score) and motor function using Unified Parkinson's Disease Rating Scale (UPDRS-part III scale).

RESULTS

The patients with PD had significantly lower MNA score than controls which correlated with plasma phosphate levels. The logistic regression revealed that increasing MNA protected from low plasma phosphate, final score (OR = 0.399; 95% CI = 0.196-0.816; p = .012) and total score (OR = 0.656; 95% CI = 0.422-1.018; p = .060). Phosphate correlated with albumin (r = .315; p < .006), transferrin (r = .331; p < .004) and cortisol (r = -0.355; p < .002) confirmed by logistic regressions. Increasing albumin protects from low phosphate after adjusting in logistic regression (OR = 0.806; 95% CI = 0.682-0.952; p = .011) and after including variables from Table 1 in backwards elimination, final step (OR = 0.800; 95% CI = 0.660-0.969; p = .022). MNA total score and cortisol correlated inversely, confirmed in logistic regression for MNA total score (OR = 0.786; 95% CI = 0.627-0.985; p = .037) and for MNA initial score (OR = 0.650; 95% CI = 0.453-0.930; p = .020).

CONCLUSION

This study highlights the importance of phosphate for optimal nutritional status by association with MNA score and albumin in plasma. An inverse relationship between phosphate and cortisol indicate, in addition, that low phosphate levels may affect cognition and motor function in PD.

High serum phosphate concentration as the result of smoking might underlie the lower risk of Parkinson's disease

Epidemiological studies have found a negative association between cigarette smoking and Parkinson's disease (PD): PD patients are approximately 50% less likely to have smoked cigarettes than age- and sex-matched controls. In both women and men, the PD protection effect of smoking may be explained by higher levels of phosphate in serum (S-P) and triglycerides (S-TG) in smokers compared to non-smokers. That is, the protecting effect from smoking could be mediated by either a high S-P or high S-TG levels. I suggest that higher S-P as the result of smoking may be associated with intracellular depletion of Pi in skeletal muscle and that this depletion of Pi is associated with increased availability of phosphate for the brain. This increased phosphate availability would protect against PD, as oxidative phosphorylation in the mitochondria is a central and persistent phenomenon in the pathogenesis cascade of PD. Phosphate is necessary for energy production in the form of creatine phosphate (CP) and adenosine-tri-phosphate (ATP) in the brain and skeletal muscle. As such, hypophosphatemia increases risk of cell death. In some clinical instances, this energy depletion may pre-dispose to dopamine neuron death. Mitochondrial dysfunction is associated with the generation of oxidative stress and mediates the induction of apoptosis. Studies with NMR spectroscopy reveal that an energy deficit in brain cells is a strong mark for PD although this differed for men and women. Compared to women, men had lower serum phosphate and ATP levels in the brain (about 15% lower). In addition to sex differences, age, stress, and malnutrition may cause low serum phosphate levels, a situation that could contribute to the lack of energy available to the brain and the risk of PD. As hypophosphatemia is present in overnutrition and has an inverse relation with a high BMI, both obesity and malnutrition are considered to be presumptive risk factor for PD.