Breastfed Infants With Spells, Tremor, or Irritability: Rule Out Vitamin B12 Deficiency.

BACKGROUND: In Norway, 5-10% of neonates and infants have biomarkers suggesting vitamin B12 deficiency from newborn screening tests and unselected clinical screening, respectively. AIMS: The aims were to identify risk factors and describe presenting symptoms and biochemical profiles in infants diagnosed with vitamin B12 deficiency. METHODS: In this case-control study, we searched hospital medical records for infants younger than one year born in 2011-2018, diagnosed with vitamin B12 deficiency. We compared 85 cases with a control group of 252 infants aged 3-7 months. Parents completed questionnaires. RESULTS: Of the 85 cases with vitamin B12 deficiency, 80% presented with spells (37%) of apneas, motor seizures, or absences within the first two months of life. Tremor (29%) and irritability (18%) were the most common findings at the first examination. Serum total homocysteine ≥10 µmol/L was found in 77% of cases compared to 28% of controls (P < 0.001). None of the mothers were vegetarians, but 25% reported a previous history of vitamin B12 deficiency and 7% had celiac disease. The dose of nitrous oxide given during labor was significantly associated with infant serum total homocysteine level at diagnosis (r = 0.37, 95% confidence interval = 0.16-0.55, P < 0.001) for cases, but not for controls. CONCLUSION: Spells, tremor, and irritability are common findings in early infant vitamin B12 deficiency. Nitrous oxide given during labor is proposed as a contributing risk factor to the development of early infant vitamin B12 deficiency.

The prevalence and clinical relevance of hyperhomocysteinemia suggesting vitamin B12 deficiency in presumed healthy infants.

BACKGROUND: Previous studies have demonstrated a high prevalence of biochemical vitamin B12 deficiency in infants in Norway. Increased total homocysteine (tHcy) is the most important marker of B12 deficiency in infants. There is a need to evaluate its clinical relevance. AIMS: To investigate the prevalence of hyperhomocysteinemia (S-tHcy > 8 µmol/L) suggestive of suboptimal B12 status and the prevalence of clinically relevant hyperhomocysteinemia in presumed healthy infants in Norway. Further, to evaluate risk factors, presence of symptoms and psychomotor development in these children. METHODS: In a prospective study we clinically examined 252 infants aged 3-7 months using standardized neurological and psychomotor tests prior to analyzing biochemical B12 deficiency markers in 250 infants. RESULTS: Twenty-five of 250 (10%) infants had hyperhomocysteinemia combined with clinically relevant symptoms suggestive of B12 deficiency. Hyperhomocysteinemia was associated with tremor, excessive sleep, and sub-normal scores in the fine motor section of the Ages and Stages Questionnaire. One-hundred and fourteen of 250 (46%) infants had hyperhomocysteinemia. Multiple regression analysis showed months of infant formula use as the strongest negative predictor for hyperhomocysteinemia. CONCLUSION: We have demonstrated associations between symptoms suggestive of infant B12 deficiency and increased levels of tHcy in presumed healthy infants The combination of hyperhomocysteinemia and associated relevant symptoms suggestive of B12 deficiency was a common finding, albeit most infants with hyperhomocysteinemia did not show symptoms.

Falsely markedly elevated 25-hydroxyvitamin D in patients with monoclonal gammopathies.

OBJECTIVES: Monoclonal immunoglobulins can cause interference in many laboratory analyses. During a 4 month period we observed seven patients with monoclonal disease and falsely extremely elevated 25-hydroxyvitamin D (25(OH)D) results above 160 ng/mL (>400 nmol/L) measured using an immunoassay from Abbott Diagnostics. Based on these findings, we studied the occurrence of falsely elevated 25(OH)D in samples with paraproteins and investigated possible mechanisms of the observed interference. METHODS: 25(OH)D was analyzed using the Architect i2000 platform from Abbott Diagnostics and a higher order method, liquid chromatography-mass spectrometry (LC-MS/MS), in serum samples from 50 patients with known monoclonal disease. Patients with falsely elevated 25(OH)D were included in further studies to elucidate the cause of interference. Spuriously elevated results were in addition analyzed on two alternative platforms (Siemens and Roche). RESULTS: Falsely elevated 25(OH)D levels were present in eight patients on the Abbott analyzer and one on the Siemens platform. Results from Roche were comparable with LC-MS/MS. Additional investigations excluded elevated concentrations of rheumatoid factor and heterophilic antibodies as the cause of interference in the Abbott assay. CONCLUSIONS: Laboratories should be aware of the risk of falsely elevated 25(OH)D in samples run on the Architect analyzer from patients with monoclonal disease. Highly elevated vitamin D results should be diluted and if the dilution is non-linear, rerun by a different method, preferably LC-MS/MS. In patients with spuriously elevated 25(OH)D without known monoclonal disease, the laboratory should consider requesting protein electrophoresis to exclude paraprotein interference.

Week-to-week biological variation of methylmalonic acid and homocysteine in healthy women.

Metylmalonic acid (MMA) and homocysteine (HCY) are important biomarkers in the assessment of cobalamin and folate metabolism. Correct interpretation of patient results benefit from knowledge of biological variation. The aim of the present study was to determine within-subject (CVI) and between-subject (CVG) biological variations of serum MMA and HCY in healthy women. We collected blood samples from 12 healthy volunteers (33-61 years) on the same weekday for 10 consecutive weeks. Samples were stored at -80 °C until analysis in duplicate in a single analytical run in random order. The CVI and CVG biological variations were estimated by CV-ANOVA after the data were first subjected to outlier and homogeneity analysis. The CVI (95% CI) for MMA and HCY were 7.2% (6.1-8.5) and 7.4% (6.5-8.5), respectively. The corresponding CVG were 21.1% (14.0-32.2) and 24.2% (16.2-36.8). The index of individuality (II) was 0.34 for MMA and 0.31 for HCY and the reference change value (RCV) was -17.7; 21.0 (% decrease; increase) for MMA and -16.2; 19.4 for HCY. We provide within- and between-subject biological variation estimates for MMA and HCY in healthy women using an updated protocol. The results will contribute to a better clinical interpretation of these biomarkers and be of aid when setting analytical performance specifications.

Biological variation of holotranscobalamin and cobalamin in healthy individuals.

Data on biological variation for cobalamin and holotranscobalamin (holoTC) are limited. The aim of this study was to determine within-subject (CVI) and between-subject (CVG) biological variations for these analytes in a healthy population. We collected blood samples from 15 healthy volunteers (12 women and three men, 22-66 years) on the same weekday for 10 consecutive weeks. Serum samples were stored at -80 °C until analysis in duplicate in a single analytical run. The CVI and CVG were estimated by nested ANOVA. The CVI (95% CI) for cobalamin and holoTC was 6.7% (5.7-7.7) and 13.0% (11.5-15.0), respectively. The corresponding CVG was 24.1% (16.4-36.0) and 24.6% (16.3-37.7). The analytical variation (CVA) (95% CI) was 3.5% (3.2-4.0) for cobalamin and 2.4% (2.1-2.6) for holoTC. The index of individuality (II) was low (<0.6) for both cobalamin and holoTC and the reference change value (RCV) was 20.1% for cobalamin and 36.6% for holoTC. Our study describes the components of biological variation of cobalamin and holoTC in a healthy population, contributing to a better clinical interpretation of these biomarkers.

Intensive educational efforts combined with external quality assessment improve the preanalytical phase in general practitioner offices and nursing homes.

BACKGROUND: Errors in the preanalytical phase in clinical laboratories affect patient safety. The aim of this study was to evaluate the effect of intensive educational efforts together with external quality assessment (EQA) of the preanalytical phase from 2013 to 2015 to improve patient identification in primary health care in Norway. In addition, routines for venous and capillary blood sampling were investigated. METHODS: A preanalytical EQA was circulated in 2013 by the Norwegian Quality Improvement of Laboratory Examinations (Noklus) to general practitioner offices and nursing homes (n=2000) to obtain information about important issues to focus on before launching an intensive educational program with courses, posters and visits in 2013-2015. Preanalytical EQA surveys were further circulated in 2014 and 2015. RESULTS: The response rate varied between 42% and 55%. The percentages of participants asking for the patients' name and the Norwegian identification number increased from about 8% in 2013 to about 35% in 2015. The increase was similar for those participating in only one EQA survey and for those who participated in EQA surveys both in 2013 and 2015. Guidelines for venous and capillary blood sampling were not always followed. CONCLUSIONS: Educational efforts more than the preanalytical EQA influenced the actions and resulted in an increase in the percentages of participants that followed the guidelines for patient identification. Some aspects of blood sampling routines need improvement.

Low serum creatinine is associated with type 2 diabetes in morbidly obese women and men: a cross-sectional study.

BACKGROUND: Low skeletal muscle mass is associated with insulin resistance and metabolic syndrome. Serum creatinine may serve as a surrogate marker of muscle mass, and a possible relationship between low serum creatinine and type 2 diabetes has recently been demonstrated. We aimed to validate this finding in a population of Caucasian morbidly obese subjects. METHODS: Cross-sectional study of 1,017 consecutive morbidly obese patients with an estimated glomerular filtration rate >60 ml/min/1.73 m2. Logistic regression (univariate and multiple) was used to assess the association between serum creatinine and prevalent type 2 diabetes, including statistically testing for the possibility of non-linearity in the relationship by implementation of Generalized Additive Models (GAM) and piecewise linear regression. Possible confounding variables such as age, family history of diabetes, waist-to-hip ratio, hypertension, current smoking, serum magnesium, albuminuria and insulin resistance (log HOMA-IR) were adjusted for in three separate multiple logistic regression models. RESULTS: The unadjusted GAM analysis suggested a piecewise linear relationship between serum creatinine and diabetes. Each 1 mumol/l increase in serum creatinine was associated with 6% (95% CI; 3%-8%) and 7% (95% CI; 2%-13%) lower odds of diabetes below serum creatinine levels of 69 and 72 mumol/l in women and men, respectively. Above these breakpoints the serum creatinine concentrations did not reduce the odds further. Adjustments for non-modifiable and modifiable risk factors left the piecewise effect for both women and men largely unchanged. In the fully adjusted model, which includes serum magnesium, albuminuria and log HOMA-IR, the piecewise effect for men was statistically non-significant, but it remained present for women. Patients with creatinine levels below median had approximately 50% (women) and 75% (men) increased odds of diabetes. CONCLUSIONS: Low serum creatinine is a predictor of type 2 diabetes in Caucasian morbidly obese patients, independent of age, gender, family history of diabetes, anthropometric measures, hypertension, and current smoking. Longitudinal studies of both obese and non-obese populations are needed to investigate whether serum creatinine may be causally linked with type 2 diabetes, and if so, precisely how they are linked.

[Trends in the diagnosis and management of neonatal hyperbilirubinaemia]. / Endring i diagnostikk og behandling av hyperbilirubinemi hos nyfødte.

BACKGROUND: The guidelines for diagnosis and treatment of neonatal hyperbilirubinaemia were changed at Vestfold Hospital, Norway in 1994 and 2007. Universal screening for ABO-immunization was implemented in 2006. This article describes effects of these changes. MATERIAL AND METHODS: Blood-type immunization, phototherapy and exchange transfusions were prospectively recorded in the 21-year period 1988-2008. Three cohorts comprised the basis for the analyses: infants born in the time-periods 1988-93, 1994-2006 or 2007-2008. RESULTS: 6.2 % of the infants born 1988-93 and 6.7 % born 1994-2006 received phototherapy. Physiological hyperbilirubinaemia in term infants was the main reason for phototherapy in the first cohort, while it was hyperbilirubinemia in preterm infants in the second cohort. 4.8 % of the infants born 2007-8 received phototherapy. Exchange transfusion was performed in 0.02 % born 1994-2008 and 0.2 % born 1988-93. Such transfusions were undertaken more frequently in cases with RhD-immunization (7.8 %) than in those with ABO-immunization (2.0 %). Universal screening for ABO-immunization increased the percentage of diagnosed cases in the population from 2.1 % to 3.6 %. No case of kernicterus was diagnosed. INTERPRETATION: Fewer term infants were treated with phototherapy for hyperbilirubinaemia after the changes of therapeutic guidelines in 1994, while more preterm infants were treated after this change. Far less exchange transfusions are performed nowadays than before 1994. ABO-immunization has been diagnosed more often after implementation of universal screening.

Fasting plasma glucose in the screening for type 2 diabetes in morbidly obese subjects.

BACKGROUND: Higher mortality rates among morbidly obese (BMI of > or =40 or > or =35 kg/m2 with weight-related comorbidities) subjects are mainly explained by comorbidities such as type 2 diabetes. As bariatric surgery ameliorates diabetes, obese diabetic subjects will receive great benefits from bariatric surgery. Screening for diabetes prior to surgical referral is therefore crucial. METHODS: We studied 1,253 consecutively recruited (2005-2008) morbidly obese subjects (67% women). Among subjects without known diabetes, 70% (670/961) performed an oral glucose tolerance test (OGTT). Screen-detected diabetes was defined as fasting plasma glucose (fPG) > or =7.0 mmol/l and/or 2-h glucose concentration (2hPG) > or = 11.1 mmol/l. RESULTS: Within the study population, 31% had diabetes, of which 8% were screen-detected. Eighty percent of those with screen-detected diabetes were diagnosed by fPG. In subjects with nondiabetic fPG concentrations, elevating the fPG cutoff value from 5.2 mmol/l to the World Health Organization's (WHO's) recommended value of 6.1 mmol/l reduced the percentage of the population needing an OGTT considerably (78-23%), but only slightly reduced the sensitivity of fPG in detecting a diabetic 2hPG concentration (100-77%). Only 7% of the patients with fPG between 6.1 and 6.9 mmol/l had a diabetic 2hPG concentration. Following the WHO's recommendations, we found that 95% of all subjects with unknown diabetes were identified. CONCLUSIONS: Fasting glucose identified four out of five morbidly obese subjects with unknown diabetes. A supplemental OGTT in selected persons identified the majority of the remaining diabetic cases.

Validation of the Hemo_Control instrument for determination of B-haemoglobin concentration in primary health care.

OBJECTIVE: The aim of this study was to evaluate the analytical performance of a new portable haemoglobinometer, Hemo_Control (EKF-diagnostic, GmbH, Germany), which measures haemoglobin concentration in venous and capillary samples. METHOD: The within series and between series imprecision of the Hemo_Control instrument were calculated after measuring the concentration of venous samples under standardized conditions; by experienced laboratory technicians in a hospital laboratory, and venous and capillary samples under conditions similar to where the instrument is intended for use; by personnel at two primary health care centres. The bias of the Hemo_Control instrument was calculated as the difference between its results and results obtained with a Coulter LH 750 instrument traceable to the ICSH reference method. RESULTS: The uncertainty of the Hemo_Control instrument for venous samples was lower than the quality goal of +/- 5% considered acceptable for patient care. High within series imprecision (5.5%) was observed for measurements of capillary blood samples in one of the primary care centres, whereas adequate analytical performance was obtained at the other centre. The Hemo_Control instrument showed negligible bias of +0.8 g/L for both venous and capillary samples in primary health care. CONCLUSION: The observed uncertainty indicates that Hemo_Control is appropriate for near patient testing using venous samples. Capillary samples may be used if sampling skills are adequate.

Anthropometric characteristics and type 2 diabetes in extremely obese Caucasian subjects: a cross-sectional study.

The associations between various anthropometric characteristics and type 2 diabetes were assessed in 1003 consecutive extremely obese Caucasian patients. Unlike BMI, measures of central obesity, and particularly WHR, were independently associated with type 2 diabetes.

Inflammatory mediators in morbidly obese subjects: associations with glucose abnormalities and changes after oral glucose.

OBJECTIVE: To explore inflammatory mediators in morbidly obese (MO) subjects with various categories of glucose tolerance and to study the changes in these mediators after an oral glucose load. DESIGN: Cross-sectional and experimental study. METHODS: A total of 144 MO subjects were classified into three categories: normal glucose tolerance (NGT); pre-diabetes; and new onset diabetes mellitus (NODM) were included, as were 27 normal weight normoglycemic controls. Serum osteoprotegerin (OPG), visfatin, leptin, adiponectin, interleukin-1 receptor antagonist (IL-1Ra), and C-reactive protein (CRP) were analyzed during an oral glucose tolerance test (OGTT). RESULTS: Fasting levels of leptin and IL-1Ra were consistently higher in obese persons (P<0.001 and P<0.05). MO subjects with NGT had higher CRP levels (P<0.001) and lower adiponectin levels (P<0.05) compared to controls. Yet when compared with MO subjects with NODM, those with NGT had lower CRP levels and higher adiponectin levels (both P<0.05). Baseline OPG and visfatin levels did not differ between the groups (P=0.326 and P=0.198). During OGTT, OPG levels decreased (P<0.001) and visfatin levels increased transiently (P=0.018). The response in OPG and visfatin did not differ between the groups (P=0.690 and P=0.170). There were minor changes in adiponectin and leptin levels. CONCLUSIONS: Morbid obesity and glucose intolerance were associated with lower adiponectin levels and higher CRP levels, thus supporting a relationship between obesity, glucose homeostasis, and inflammation. Oral glucose suppressed OPG levels and transiently enhanced visfatin levels independent of obesity and glucose tolerance status, indicating that glucose may be involved in the acute regulation of these proteins.

Parathyroid hormone, but not vitamin D, is associated with the metabolic syndrome in morbidly obese women and men: a cross-sectional study.

BACKGROUND: The prevalence of vitamin D insufficiency and secondary hyperparathyroidism is high among morbidly obese subjects. Further, low serum levels of 25-hydroxyvitamin D (25 [OH]D) and magnesium have been associated with increased risk of the metabolic syndrome (MS), and recently, a possible link between PTH and MS has been reported. Although it is well known that the synthesis and secretion of PTH is regulated by serum levels of calcium, phosphate, magnesium and 25(OH)D, less is known about the possible clustered affiliation of these parameters with MS. We aimed to explore whether MS is associated with abnormal serum levels of PTH, 25(OH)D and magnesium in a population of morbidly obese patients. METHODS: Fasting serum levels of 25(OH)D, PTH and magnesium were assessed in a cross-sectional cohort study of 1,017 consecutive morbidly obese patients (68% women). Multiple logistic regression analyses were used to assess the independent effect of PTH, 25(OH)D and magnesium on the odds for MS (National Cholesterol Education Program [NCEP]) after adjustment for confounding factors. RESULTS: Sixty-eight percent of the patients had MS. Patients with MS had lower mean serum magnesium (P < 0.001) and higher mean PTH (P = 0.067) than patients without MS, whereas mean 25(OH)D did not differ significantly. Patients with PTH levels in the second to fourth quartiles had higher odds of prevalent MS (odds ratio 1.47 [95% CI 0.92-2.35], 2.33 [95% CI 1.40-3.87] and 2.09 [95% CI 1.23-3.56], respectively), after adjustment for 25(OH)D, magnesium, calcium, phosphate, creatinine, age, gender, season of serum sampling, BMI, current smoking, albuminuria, CRP, insulin resistance and type 2 diabetes. Further, PTH was significantly correlated with systolic and diastolic pressure (both P < 0.001), but not with the other components of MS. The levels of 25(OH)D and magnesium were not associated with MS in the multivariate model. CONCLUSION: The PTH level, but not the vitamin D level, is an independent predictor of MS in treatment seeking morbidly obese Caucasian women and men. Randomized controlled clinical trials, including different therapeutic strategies to lower PTH, e.g. calcium/vitamin D supplementation and weight reduction, are necessary to explore any cause-and-effect relationship.