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BACKGROUND: An analytical benchmark for high-sensitivity cardiac troponin (hs-cTn) assays is to achieve a coefficient of variation (CV) of ≤ 10.0 % at the 99th percentile upper reference limit (URL) used for the diagnosis of myocardial infarction. Few prospective multicenter studies have evaluated assay imprecision and none have determined precision at the female URL which is lower than the male URL for all cardiac troponin assays. METHODS: Human serum and plasma matrix samples were constructed to yield hs-cTn concentrations near the female URLs for the Abbott, Beckman, Roche, and Siemens hs-cTn assays. These materials were sent (on dry ice) to 35 Canadian hospital laboratories (n = 64 instruments evaluated) participating in a larger clinical trial, with instructions for storage, handling, and monthly testing over one year. The mean concentration, standard deviation, and CV for each instrument type and an overall pooled CV for each manufacturer were calculated. RESULTS: The CVs for all individual instruments and overall were ≤ 10.0 % for two manufacturers (Abbott CVpooled = 6.3 % and Beckman CVpooled = 7.0 %). One of four Siemens Atellica instruments yielded a CV > 10.0 % (CVpooled = 7.7 %), whereas 15 of 41 Roche instruments yielded CVs > 10.0 % at the female URL of 9 ng/L used worldwide (6 cobas e411, 1 cobas e601, 4 cobas e602, and 4 cobas e801) (CVpooled = 11.7 %). Four Roche instruments also yielded CVs > 10.0 % near the female URL of 14 ng/L used in the United States (CVpooled = 8.5 %). CONCLUSIONS: The number of instruments achieving a CV ≤ 10.0 % at the female 99th-percentile URL varies by manufacturer and by instrument. Monitoring assay precision at the female URL is necessary for some assays to ensure optimal use of this threshold in clinical practice.
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Infarto del Miocardio , Humanos , Masculino , Femenino , Estudios Prospectivos , Canadá , Infarto del Miocardio/diagnóstico , Bioensayo , Troponina , Troponina T , Biomarcadores , Valores de ReferenciaRESUMEN
Kratom is a plant originating in Southeast Asia that has been used for its dose-dependent stimulant and opioid effects. The main active compound in kratom is mitragynine, an alkaloid with affinity for the mu-opioid receptor. Toxicity and fatalities related to kratom use have increased substantially in recent years. In this case report, we describe a 44-year-old man who was found deceased in bed. The only significant finding at autopsy was abdominal distension with >4 L of ascites. Toxicology testing was performed on femoral blood which showed 79 ng/mL of hydromorphone, 560 ng/mL of mitragynine, and 240 ng/mL of olanzapine. In addition, creatinine and urea in vitreous humor were significantly elevated, consistent with renal impairment. Death was attributed to hydromorphone toxicity with mitragynine being a contributing factor.
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Sobredosis de Droga , Mitragyna , Alcaloides de Triptamina Secologanina , Masculino , Humanos , Adulto , Hidromorfona , Extractos Vegetales , Analgésicos OpioidesRESUMEN
OBJECTIVES: Monitoring quality indicators (QIs) is an important part of laboratory quality assurance (QA). Here, the Canadian Society of Clinical Chemists (CSCC) Point of Care Testing (POCT) and QI Special Interest Groups describe a process for establishing and monitoring QIs for POCT glucose testing. METHODS: Key, error prone steps in the POCT glucose testing process were collaboratively mapped out, followed by risk assessment for each step. Steps with the highest risk and ability to detect a non-conformance were chosen for follow-up. These were positive patient identification (PPID) and repeat of critically high glucose measurements. Participating sites were asked to submit aggregate data for these indicators from their site(s) for a one-month period. The PPID QI was also included as part of a national QI monitoring program for which fifty-seven sites submitted data. RESULTS: The percentage of POCT glucose tests performed without valid PPID ranged from 0-87%. Sites without Admission-Discharge-Transfer (ADT) connectivity to POCT meters were among those with the highest percentage of POCT glucose tests performed without valid PPID. The percentage repeated critically high glucose measurements ranged from 0-50%, indicating low compliance with this recommendation. A high rate of discordance was also noted when critically high POCT glucose measurements were repeated, demonstrating the importance of repeat testing prior to insulin administration. CONCLUSIONS: Here, a process for establishing these QIs is described, with preliminary data for two QIs chosen from this process. The findings demonstrate the importance of QIs for identification and comparative performance monitoring of non-conformances to improve POCT quality.
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Glucosa , Sistemas de Atención de Punto , Indicadores de Calidad de la Atención de Salud , Canadá , Opinión Pública , Glucosa/química , Pruebas en el Punto de Atención , HumanosRESUMEN
OBJECTIVE: The BD Vacutainer® Barricor™ plasma blood collection tube uses a mechanical separator during centrifugation to separate plasma from the cellular elements of blood. Compared to use of plasma separator tubes (PST™) with gel, Barricor™ produces a cleaner sample with less residual cellular content. We sought to determine if Barricor™ reduces pre-analytical error compared to PST™. DESIGN & METHODS: We used a model previously published that utilizes serial differences between intra-patient measurements transformed into a Taylor series of variation vs time with the y-intercept equal to the sum of short-term analytic variation, preanalytic variation and biologic variation. The intra-patient variation of chloride, sodium, potassium, and troponin-T (hs-TnT) obtained from the Emergency Department of a large tertiary care center sampled with PST™ (May 2015-April 2018, n = 59,762 specimens) or Barricor™ (May 2018-May 2021, n = 61,512 specimens) was evaluated. All specimens were analyzed on either Roche Modular or Cobas® instruments. For each analyte, pairs of intra-patient results were tabulated and separated by 1 h intervals. The average between-pair variations were then regressed against time. We also determined the number of intra-patient outliers using the reference change value for each analyte. RESULTS: The Barricor™ hs-TnT y-intercept (-0.0132) was significantly lower than the PST™ intercept (0.9109; p = 0.022). This was also true for chloride (y-intercept = 1.0067 in Barricor™ and 1.3431 in PST™, p = 0.037). The percentage of hs-TnT outliers was significantly lower in Barricor™ (8.32 %) vs PST™ (12.2 %; p < 0.001). CONCLUSION: The analytical and biological variations are assumed to be steady over the study periods; we ascribe the difference in the y-intercept to the preanalytical effect of the Barricor™ tube reducing platelets and other cellular debris.
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Cloruros , Troponina , Humanos , Estudios Retrospectivos , Recolección de Muestras de Sangre/métodos , Manejo de Especímenes , Troponina TRESUMEN
INTRODUCTION: Since recreational legalization of cannabis in Canada in 2018, self-reported use in New Brunswick (NB) has increased from 15.1% to 20.3%, the largest increase of any province. Current literature on the impact of recreational cannabis legislation in other jurisdictions is conflicting, though retail availability has often been delayed on enactment. Given the immediate availability of cannabis in NB after legalization, we sought to establish the effect this had on post-mortem cannabinoid detection. Furthermore, we wanted to investigate the impact that age, sex, and manner of death had on cannabis use. We also established if there were any increases in commonly detected drugs over the study period. METHODS: A retrospective chart review was conducted on all adult Coroner's cases with toxicology analysis in NB between January 2014 and May 2020 (n = 3060). Differences in the proportion of cannabinoid-positive samples pre- versus post-legalization in the overall cohort as well as within each demographic parameter were assessed using chi-square tests. The effects of demographic parameters on cannabis presence were further assessed by logistic regression. Lastly, chi-square tests for trend were performed to identify increasing trends in cannabis detection, as well as cocaine, ethanol, opiates/opioids, benzodiazepines, and amphetamines over the study period. RESULTS: After controlling for age, sex, and manner of death, participants that died after recreational legalization had higher odds of having cannabis present post-mortem than those that died pre-legalization. In addition, demographic sub-analysis identified a greater proportion of cannabinoid-positive samples post-legalization in 25- to 44-year-olds and in deaths classified as either suicide or accidental compared to pre-legalization. We also observed a significant increase in the presence of cocaine and amphetamines in post-mortem samples over the study period. CONCLUSION: This study demonstrates that cannabis use has increased post-legalization in NB, particularly within young adults and those dying by suicide or accidental means. It also highlights the need for future research into the impact that legalization has on cannabis use in other jurisdictions.
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Cannabinoides , Cannabis , Cocaína , Alucinógenos , Analgésicos , Analgésicos Opioides , Agonistas de Receptores de Cannabinoides , Humanos , Legislación de Medicamentos , Nuevo Brunswick , Estudios Retrospectivos , Adulto JovenRESUMEN
INTRODUCTION: The type of blood collection tube used when obtaining samples for therapeutic drug monitoring (TDM) has important implications on the accuracy of results. Serum tubes without a gel separator are currently considered best practice. We sought to evaluate the performance of Barricor™, a novel plasma tube that utilizes an inert mechanical separator, as well as a gel-based tube (PST™) for testing acetaminophen, digoxin, gentamicin, methotrexate, phenobarbital, phenytoin, salicylate, vancomycin, valproic acid, carbamazepine, and theophylline on a Roche Cobas® 8000 platform. METHODS: Paired patient samples were collected from individuals taking at least one of the medications evaluated. These were supplemented with spiked specimens to ensure a minimum of 40 paired samples per drug. All drugs were measured within two hours of collection on Roche e602 or c502 instruments. Deming regression was used to assess bias between Barricor™ vs serum and PST™ vs serum. Seven-day refrigerated stability was also assessed in Barricor™, PST™, and serum tubes in a subset of samples (n = 10) for each drug. RESULTS: Drug concentrations in Barricor™ were similar to serum for each drug assessed. In contrast, a negative bias was observed in PST™ compared to serum tubes for carbamazepine (-7.6%) and phenytoin (-6.8%) although this did not surpass our total allowable error goal of 10%. All drugs recovered within ±10% of baseline value when samples were stored refrigerated for 7 days except for carbamazepine, phenytoin, and phenobarbital where significant analyte loss was observed within the first day in PST™ tubes. CONCLUSION: Barricor™ tubes are a suitable alternative to serum for TDM on the Roche Cobas® 8000 platform.
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Conservación de la Sangre , Recolección de Muestras de Sangre , Monitoreo de Drogas , Conservación de la Sangre/instrumentación , Conservación de la Sangre/métodos , Recolección de Muestras de Sangre/instrumentación , Recolección de Muestras de Sangre/métodos , Monitoreo de Drogas/instrumentación , Monitoreo de Drogas/métodos , HumanosRESUMEN
Point of Care Testing (POCT) refers to clinical laboratory testing performed outside the central laboratory, nearer to the patient and sometimes at the patient bedside. The testing is usually performed by clinical staff, such as physicians or nurses, who are not laboratory trained. This document was developed by the POCT Interest group of the Canadian Society of Clinical Chemists (CSCC) as practical guidance for quality assurance practices related to POCT performed in hospital and outside hospital environments. The aspects of quality assurance addressed in this document include: (1) device selection, (2) initial device verification, (3) ongoing device verification, (4) ongoing quality assurance including reagent and quality control (QC) lot changes, and (5) quality management including operator and document management.
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Técnicas de Laboratorio Clínico/normas , Pruebas en el Punto de Atención/normas , Garantía de la Calidad de Atención de Salud/métodos , Canadá , Humanos , Guías de Práctica Clínica como Asunto/normas , Control de CalidadRESUMEN
INTRODUCTION: Barricor™ Vacutainers® are a novel non-gel separator blood collection tube. These tubes enable faster pre-analytical processing which could reduce turnaround time and be beneficial in an acute care setting. We sought to evaluate the bias, stability, and integrity of plasma generated from these tubes compared to Plasma Separator Tubes™ (PST) for 50 routine chemistry analytes on a Roche Cobas® 8000 analyzer. METHODS: Paired samples were collected from 150 patients originating in the emergency department and outpatient collections at the Saint John Regional Hospital. Barricor™ vacutainers were centrifuged for 3â¯min at 4000g and PST™ vacutainers for 10â¯min at 1300â¯g within two hours of collection. Plasma samples (nâ¯=â¯126) were then analyzed for 50 chemistry analytes and bias determined between tubes. Ten-day stability of AST, glucose, potassium, phosphate, and LDH was also assessed in a subset of paired samples (nâ¯=â¯4). Lastly, the quality of plasma (nâ¯=â¯20) was assessed through measurement of cell counts on a DxH Hematology Analyzer. RESULTS: All 50 analytes demonstrated comparable results across a broad concentration range between Barricor™ and PST™ vacutainers (average percent bias -1.5% to 6.1%; Deming linear regression slopes 0.933-1.041; correlation coefficientsâ¯≥â¯0.9144). AST, potassium, glucose and LDH were stable for 10â¯days in Barricor™ vacutainers (change from baselineâ¯<â¯10%) but <5â¯days in PST™ vacutainers while phosphate was stable for 4â¯days in Barricor™ vs 2â¯days in PST™ vacutainers. Platelet counts were statistically lower in Barricor™ compared to PST™ vacutainers. CONCLUSION: Our data suggest that Barricor™ vacutainers are an acceptable alternative to PST™ vacutainers while offering the added benefit of decreased pre-analytical processing time, increased stability of certain analytes, and possibly less cellular contamination.
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Análisis Químico de la Sangre/instrumentación , Plasma/química , Manejo de Especímenes/instrumentación , Análisis Químico de la Sangre/métodos , Humanos , Manejo de Especímenes/métodosRESUMEN
HbA1c is used in forensic toxicology to identify undiagnosed diabetes mellitus (DM) and those with poor glycemic control prior to death. HbA1c is typically measured in whole blood collected in tubes containing ethylenediaminetetraacetic acid (EDTA). The effect of other additives, including sodium fluoride (NaF), is unclear. Furthermore, the assessment of short- and long-term stability of HbA1c has produced conflicting results. In this study, we collected paired postmortem blood samples in EDTA and NaF tubes (n = 142) to assess their comparability for HbA1c measurement. Stability was assessed by measuring HbA1c at baseline, 2, 3, and 4 weeks postcollection (stored at 4°C) and at 2, 4, 6, and 12 months postcollection (stored at -20°C). We found no significant difference in HbA1c between the two preservatives at any of the time points indicating NaF is a suitable preservative for HbA1c measurement. We also determined that DM status, postmortem interval, and decomposition had no effect on stability.
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Ácido Edético , Fijadores , Hemoglobina Glucada/análisis , Fluoruro de Sodio , Manejo de Especímenes , Diabetes Mellitus/sangre , Medicina Legal , Humanos , Modelos Lineales , Cambios Post Mortem , Estaciones del Año , Factores de TiempoRESUMEN
Testosterone, the most abundant androgen in men, is a steroid hormone that is synthesized predominantly by the testes. In women, minor amounts are synthesized in the ovaries. Androgen precursors are also produced and secreted from the adrenal glands in both sexes, where they undergo peripheral conversion to testosterone. Circulating concentrations are approximately 15-25 times higher in adult men compared to women. Maintenance of these levels is necessary for development and maintenance of secondary sexual characteristics, libido, growth, prevention of osteoporosis, and most importantly in men, spermatogenesis. Most testosterone circulates tightly bound to sex hormone-binding globulin (SHBG) or weakly bound to albumin. A minor amount circulates as free testosterone, and it is believed that this is the metabolically active fraction. Measurement of free testosterone is important in the diagnosis of many diseases, most importantly disorders of androgen deficiency in men (i.e., hypogonadism) and androgen excess in women (i.e., polycystic ovary syndrome and hirsutism). Many methodologies are available for free testosterone measurement including the reference methods (equilibrium dialysis and ultrafiltration), analog immunoassay, and calculated free testosterone based on measurement of total testosterone, SHBG, and albumin. Moreover, measurement of bioavailable testosterone, a combination of albumin-bound and free testosterone, also has clinical utility and can be measured by selective protein precipitation or calculation. In this review, the advantages and limitations of each of these methods will be discussed in the context of clinical utility and implementation into a routine hospital laboratory. Furthermore, up and coming methodologies for free testosterone measurement, including liquid chromatography-tandem mass spectrometry, will also be discussed.
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Testosterona/sangre , Diálisis , Femenino , Humanos , Masculino , Espectrometría de Masas , Caracteres Sexuales , Testosterona/deficiencia , Testosterona/fisiología , UltrafiltraciónRESUMEN
BACKGROUND: Pediatric endocrinopathies are commonly diagnosed and monitored by measuring hormones of the hypothalamic-pituitary-gonadal axis. Because growth and development can markedly influence normal circulating concentrations of fertility hormones, accurate reference intervals established on the basis of a healthy, nonhospitalized pediatric population and that reflect age-, gender-, and pubertal stage-specific changes are essential for test result interpretation. METHODS: Healthy children and adolescents (n = 1234) were recruited from a multiethnic population as part of the CALIPER study. After written informed parental consent was obtained, participants filled out a questionnaire including demographic and pubertal development information (assessed by self-reported Tanner stage) and provided a blood sample. We measured 7 fertility hormones including estradiol, testosterone (second generation), progesterone, sex hormone-binding globulin, prolactin, follicle-stimulating hormone, and luteinizing hormone by use of the Abbott Architect i2000 analyzer. We then used these data to calculate age-, gender-, and Tanner stage-specific reference intervals according to Clinical Laboratory Standards Institute C28-A3 guidelines. RESULTS: We observed a complex pattern of change in each analyte concentration from the neonatal period to adolescence. Consequently, many age and sex partitions were required to cover the changes in most fertility hormones over this period. An exception to this was prolactin, for which no sex partition and only 3 age partitions were necessary. CONCLUSIONS: This comprehensive database of pediatric reference intervals for fertility hormones will be of global benefit and should lead to improved diagnosis of pediatric endocrinopathies. The new database will need to be validated in local populations and for other immunoassay platforms as recommended by the Clinical Laboratory Standards Institute.
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Hormonas Gonadales/sangre , Hormonas Peptídicas/sangre , Adolescente , Niño , Preescolar , Estudios de Cohortes , Estradiol/sangre , Femenino , Hormona Folículo Estimulante/sangre , Humanos , Inmunoensayo , Lactante , Recién Nacido , Hormona Luteinizante/sangre , Masculino , Progesterona/sangre , Prolactina/sangre , Valores de Referencia , Globulina de Unión a Hormona Sexual/análisis , Testosterona/sangreRESUMEN
Abstract Levamisole is an anthelminthic that was first used as a de-worming agent in humans and animals. It has also been used to treat inflammatory conditions as well as certain types of cancer. Levamisole was discontinued for human use in the early 21st century due to toxic side effects including agranulocytosis and vasculitis. Recently, levamisole was discovered as a cocaine adulterant after reports emerged of drug users with the above disorders. As the prevalence of cocaine usage has grown in the last 15 years, measurement of levamisole in human samples has become increasingly important. This review focuses on the various bioanalytical methods available for the determination of levamisole in human plasma and urine. Earlier methods employed gas chromatography coupled with nitrogen-selective thermionic specific detection and nitrogen-phosphorus detection, as well as high performance liquid chromatography coupled with ultraviolet detection. In addition, gas chromatography-mass spectrometry (GC-MS) and high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) have also been described. Currently, GC-MS appears to be the method of choice however recent developments in the area of LC-MS/MS make this technology an attractive alternative. The merits of both GC-MS and LC-MS/MS for the determination of levamisole are evaluated on the basis of sample preparation, chromatographic separation conditions, run time, and analytical performance. In addition, emerging methods in this area are also reviewed.
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Cocaína/química , Contaminación de Medicamentos , Levamisol/sangre , Levamisol/orina , Animales , Cromatografía de Gases , Cromatografía Líquida de Alta Presión , Humanos , Espectrometría de MasasRESUMEN
BACKGROUND: Peptide YY (PYY), a gut hormone that inhibits appetite, has been linked to the development of obesity. OBJECTIVE: This study investigated the nutritional regulation of PYY after 7 d of overfeeding (70% above normal energy requirements) in normal-weight, overweight, and obese men. DESIGN: Sixty-nine men (aged 19-29 y) participated in the study. We analyzed the relation between fasting serum PYY before and after a 7-d overfeeding challenge in normal-weight, overweight, and obese men. In addition, we analyzed PYY with obesity-related phenotypes including weight, percentage body fat (measured by dual-energy X-ray absorptiometry), body mass index (BMI), total cholesterol, HDL, LDL, glucose, insulin, insulin resistance, and ß cell function evaluated by the homeostasis model assessment of insulin resistance (HOMA-IR) and ß cell function (HOMA-ß) at baseline and in response to the energy surplus. RESULTS: Fasting serum PYY concentrations at baseline were not significantly different between the normal-weight, overweight, and obese subjects on the basis of dual-energy X-ray absorptiometry or BMI. Although the PYY concentration significantly increased due to overfeeding, no differences were observed between adiposity statuses. In addition, basal PYY was negatively correlated with the changes of total cholesterol, HDL, and LDL in normal weight. In addition, the increase in PYY after overfeeding was positively correlated with HDL cholesterol and glucose in normal-weight subjects. CONCLUSIONS: Our findings suggest that fasting PYY concentrations are not associated with adiposity status. Moreover, the 7-d overfeeding challenge significantly increased fasting PYY, which is likely a protective response to the positive energy balance.
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Glucemia/metabolismo , Composición Corporal , Colesterol/sangre , Ingestión de Energía , Hipernutrición/sangre , Péptido YY/sangre , Absorciometría de Fotón , Adolescente , Adulto , Índice de Masa Corporal , Humanos , Masculino , Obesidad/sangre , Sobrepeso/sangre , Valores de Referencia , Adulto JovenRESUMEN
Nearly one-third of obese (OB) people are reported to be metabolically healthy based on BMI criteria. It is unknown whether this holds true when more accurate adiposity measurements are applied such as dual-energy X-ray absorptiometry (DXA). We compared differences in the prevalence of cardiometabolic abnormalities among adiposity groups classified using BMI vs. DXA criteria. A total of 1,907 adult volunteers from Newfoundland and Labrador participated. BMI and body fat percentage (%BF; measured using DXA) were measured following a 12-h fasting period. Subjects were categorized as normal weight (NW), overweight (OW), or OB based on BMI and %BF criteria. Cardiometabolic abnormalities considered included elevated triglyceride, glucose, and high-sensitivity C-reactive protein (hsCRP) levels, decreased high-density lipoprotein (HDL) cholesterol levels, insulin resistance, and hypertension. Subjects were classified as metabolically healthy (0 or 1 cardiometabolic abnormality) or abnormal (≥ 2 cardiometabolic abnormalities). We found low agreement in the prevalence of cardiometabolic abnormalities between BMI and %BF classifications (κ = 0.373, P < 0.001). Among NW and OW subjects, the prevalence of metabolically healthy individuals was similar between BMI and %BF (77.6 vs. 75.7% and 58.8 vs. 62.5%, respectively) however, there was a pronounced difference among OB subjects (34.0 vs. 47.7%, P < 0.05). Similar trends were evident using three additional definitions to characterize metabolically healthy individuals. Our findings indicate that approximately one-half of OB people are metabolically healthy when classified using %BF criteria which is significantly higher than previously reported using BMI. Caution should therefore be taken when making inferences about the metabolic health of an OB population depending on the method used to measure adiposity.
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Absorciometría de Fotón/métodos , Composición Corporal , Índice de Masa Corporal , Enfermedades Cardiovasculares/complicaciones , Enfermedades Metabólicas/complicaciones , Obesidad/complicaciones , Adulto , Anciano , Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/epidemiología , Ayuno , Femenino , Humanos , Masculino , Enfermedades Metabólicas/diagnóstico , Enfermedades Metabólicas/epidemiología , Persona de Mediana Edad , Terranova y Labrador/epidemiología , Obesidad/diagnóstico , Obesidad/epidemiología , Prevalencia , Valores de Referencia , Adulto JovenRESUMEN
BACKGROUND: Increased protein proportions in the diet combined with energy restriction has been shown to enhance weight loss during dietary intervention. It is not known if the beneficial effect of dietary protein exists in the general population under normal living conditions without a negative energy balance. METHODS: A total of 1834 participants (n = 443 men, n = 1391 women) were recruited from the CODING study. Participants' dietary macronutrient compositions were determined through a Willett FFQ. Body composition variables including percent body fat (%BF), percent trunk fat (%TF), percent total lean mass (%LM), and percent trunk lean mass (%TLM) were determined using DXA. Major confounding factors including age, physical activity levels, total caloric intake, carbohydrate intake, menopausal status, smoking status and medication use were controlled for in all analyses. RESULTS: Significant inverse relationships were observed between dietary protein intake (g/kg body weight/day) and weight, waist circumference, waist-to-hip ratio, BMI, %BF, and %TF (P < 0.001). Significant positive relationships were observed with %LM and %TLM (P < 0.001). Additionally, significant differences in weight (12.7 kg in men, 11.4 kg in women), BMI (4.1 BMI units in men, 4.2 units in women), and %BF (7.6% in men, 6.0% in women) were observed between low and high dietary protein consuming groups (P < 0.001). Dietary protein explained 11% of the total variation in %BF in the NL population. CONCLUSION: This study provides strong evidence that higher protein intake, even in the absence of energy restriction, is associated with a more favorable body composition in the general population.