Carnosine supplementation improves glucose control in adults with pre-diabetes and type 2 diabetes: A randomised controlled trial

BACKGROUND AND AIMS

Type 2 diabetes (T2DM) is a major cause of morbidity and mortality globally. Carnosine, a naturally occurring dipeptide, has anti-inflammatory, antioxidant, and anti-glycating effects, with preliminary evidence suggesting it may improve important chronic disease risk factors in adults with cardiometabolic conditions.

METHODS AND RESULTS

In this randomised controlled trial, 43 adults (30%F) living with prediabetes or T2DM consumed carnosine (2 g) or a matching placebo daily for 14 weeks to evaluate its effect on glucose metabolism assessed via a 2-h 75 g oral glucose tolerance test. Secondary outcomes included body composition analysis by dual energy x-ray absorptiometry (DEXA), calf muscle density by pQCT, and anthropometry. Carnosine supplementation decreased blood glucose at 90 min (-1.31 mmol/L; p = 0.02) and 120 min (-1.60 mmol/L, p = 0.02) and total glucose area under the curve (-3.30 mmol/L; p = 0.04) following an oral glucose tolerance test. There were no additional changes in secondary outcomes. The carnosine group results remained significant before and after adjustment for age, sex, and change in weight (all>0.05), and in further sensitivity analyses accounting for missing data. There were no significant changes in insulin levels.

CONCLUSION

This study provides preliminary support for larger trials evaluating carnosine as a potential treatment for prediabetes and the initial stages of T2DM. Likely mechanisms may include changes to hepatic glucose output explaining the observed reduction in blood glucose without changes in insulin secretion following carnosine supplementation.

Carnosine Did Not Affect Vascular and Metabolic Outcomes in Patients with Prediabetes and Type 2 Diabetes: A 14-Week Randomized Controlled Trial

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of morbidity and mortality in patients with prediabetes and type 2 diabetes mellitus (T2DM). Carnosine has been suggested as a potential approach to reduce ASCVD risk factors. However, there is a paucity of human data. Hence, we performed a 14-week double-blind randomized placebo-controlled trial to determine whether carnosine compared with placebo improves vascular and metabolic outcomes in individuals with prediabetes and T2DM. In total, 49 patients with prediabetes and T2DM with good glycemic control were randomly assigned either to receive 2 g/day carnosine or matching placebo. We evaluated endothelial dysfunction, arterial stiffness, lipid parameters, blood pressure, heart rate, hepatic and renal outcomes before and after the intervention. Carnosine supplementation had no effect on heart rate, peripheral and central blood pressure, endothelial function (logarithm of reactive hyperemia (LnRHI)), arterial stiffness (carotid femoral pulse wave velocity (CF PWV)), lipid parameters, liver fibroscan indicators, liver transient elastography, liver function tests, and renal outcomes compared to placebo. In conclusion, carnosine supplementation did not improve cardiovascular and cardiometabolic risk factors in adults with prediabetes and T2DM with good glycemic control. Therefore, it is improbable that carnosine supplementation would be a viable approach to mitigating the ASCVD risk in these populations. The trial was registered at clinicaltrials.gov (NCT02917928).

Aldosterone, Renin, and Aldosterone-to-Renin Ratio Variability in Screening for Primary Aldosteronism

CONTEXT

The plasma aldosterone concentration (PAC), renin, and aldosterone-to-renin ratio (ARR) are used to screen for primary aldosteronism (PA). Substantial intra-individual variability of PAC and ARR using plasma renin activity in the context of usual antihypertensive therapy has been described, but there is no data on ARR variability calculated using direct renin concentration (DRC).

OBJECTIVE

To describe the intra-individual variability of PAC, DRC, and ARR in the absence of interfering medications in patients with and without PA.

DESIGN

Retrospective cohort study.

PATIENTS

Hypertensive patients referred for investigation of PA, with at least 2 ARR measurements while off interfering medications.

SETTING

Endocrine hypertension service of a tertiary center, from May 2017 to July 2021.

MAIN OUTCOME MEASURES

PAC, DRC, and ARR variability was calculated as coefficient of variation (CV) and percent difference (PD).

RESULTS

Analysis of 223 patients (55% female, median age 52 years), including 162 with confirmed PA, demonstrated high variability with a sample CV of 22-25% in the PAC and sample CV of 41% to 42% in the DRC and ARR in both the PA and non-PA groups. The degree of variability was substantially higher than the assays' analytical CV. Sixty-two patients (38%) with PA had at least one ARR below 70 pmol/L:mU/L (2.4 ng/dL:mU/L), a cut-off for first-line screening of PA.

CONCLUSIONS

Significant intra-individual variability in PAC, DRC, and hence ARR occurs in a large proportion of patients being investigated for PA. These findings support the need for at least 2 ARR before PA is excluded or further investigated.

[One case of rhabdomyolysis caused by acute phoxim poisoning]

Patients with organophosphate poisoning usually die from respiratory depression and respiratory failure. The incidence of rhabdomyolysis is relatively low, but the mortality rate is extremely high once it occurs. In this paper, the treatment of a patient with acute phoxim poisoning was analyzed. The patient developed severe rhabdomyolysis syndrome on the 3rd day of treatment, the creatine kinase exceeded the normal value by more than 300 times (up to 103510.65 U/L) , and renal failure occurred. Clinical treatment included active detoxification, blood purification, organ support, and internal environment maintenance. The patient's rhabdomyolysis continued, and the condition worsened. Finally, the family gave up the treatment and the patient died. It is suggested that attention should be paid to the occurrence of rhabdomyolysis syndrome during the treatment of organophosphorus poisoning, and timely blood purification technology may be the key to treatment.

[An investigation of a food poisoning incident caused by Amanita fuliginea]

Mistakenly picking and eating poisonous mushrooms can cause acute poisoning. In August 2020, Qingdao Hospital of Traditional Chinese Medicine handled a poisonous mushroom poisoning incident, conducted epidemiological investigation on all poisoned patients, collected suspicious food, clinical manifestations, clinical test results and treatment conditions, and identified the mushrooms as Amanita fuliginea poisoning after morphological identification. In this incident, 6 people ate grey goose paste, of which 4 were sick with a incubation period of 6~12 h. The clinical manifestations were gastrointestinal symptoms such as nausea, vomiting and diarrhea, liver and kidney damage. After symptomatic support treatment, hemoperfusion or continuous hemofiltration treatment, the patients were cured and discharged. It is suggested to strengthen the popular science education on poisonous mushroom poisoning and improve the ability of identification and clinical treatment of poisonous mushrooms in grass-roots medical institutions.

Type 2 diabetes after a pregnancy with gestational diabetes among first nations women in Australia: The PANDORA study

AIMS

To determine among First Nations and Europid pregnant women the cumulative incidence and predictors of postpartum type 2 diabetes and prediabetes and describe postpartum cardiovascular disease (CVD) risk profiles.

METHODS

PANDORA is a prospective longitudinal cohort of women recruited in pregnancy. Ethnic-specific rates of postpartum type 2 diabetes and prediabetes were reported for women with diabetes in pregnancy (DIP), gestational diabetes (GDM) or normoglycaemia in pregnancy over a short follow-up of 2.5 years (n = 325). Pregnancy characteristics and CVD risk profiles according to glycaemic status, and factors associated with postpartum diabetes/prediabetes were examined in First Nations women.

RESULTS

The cumulative incidence of postpartum type 2 diabetes among women with DIP or GDM were higher for First Nations women (48%, 13/27, women with DIP, 13%, 11/82, GDM), compared to Europid women (nil DIP or GDM p < 0.001). Characteristics associated with type 2 diabetes/prediabetes among First Nations women with GDM/DIP included, older age, multiparity, family history of diabetes, higher glucose values, insulin use and body mass index (BMI).

CONCLUSIONS

First Nations women experience a high incidence of postpartum type 2 diabetes after GDM/DIP, highlighting the need for culturally responsive policies at an individual and systems level, to prevent diabetes and its complications.

Surfactin inhibits the growth of Propionibacterium acnes by destroying the cell wall and membrane

Propionibacterium acnes plays a major role in acne vulgaris. In the pre-experiment, the growth of P. acnes was inhibited effectively using surfactin; however, the antibacterial mechanism has not been described. Therefore, the aim of this study was to evaluate antibacterial activity and analyse the mechanism of surfactin against P. acnes. Minimum inhibitory concentration, time-killing kinetics and scanning electron microscopy were used to evaluate the activity of surfactin against P. acnes, which showed that 128 μg ml^-1 effectively inhibited growth. Cell wall permeability was evaluated by detecting the extracellular alkaline phosphatase activity, which increased to 1·83- and 2·32-fold after incubating with 128 and 256 μg ml^-1 of surfactin for 10 h, respectively. Propidium iodide fluorescence, leakage of nucleic acid, protein, K⁺ , and Ca²⁺ , membrane potential and the leakage of calcein from small unilamellar vesicles all increased after incubation with surfactin, indicating that its strong biological activities act mainly by altering membrane integrity. In a mouse model of acne, surfactin significantly reduced P. acnes-induced epidermal swelling and erythema. These results indicate that surfactin effectively inhibited the growth of P. acnes by destroying the cell wall and membrane, and is a potential candidate for acne treatment.

Phagocyte extracellular traps in children with neutrophilic airway inflammation

Childhood lung infection is often associated with prominent neutrophilic airway inflammation and excess production of proteases such as neutrophil elastase (NE). The mechanisms responsible for this inflammation are not well understood. One potentially relevant pathway is the production of extracellular traps by neutrophils (NETs) and macrophages (METs). The aim of this study was to measure NET and MET expression in children and the effect of deoxyribonculease (DNase) 1 and α₁-antitrypsin (AAT) on this process.

We studied 76 children (median age of 4.0 years) with cystic fibrosis or chronic cough who underwent investigational bronchoscopy. NETs, METs and neutrophil elastase activity in bronchoalveolar lavage (BAL) samples were measured using confocal microscopy and functional assays. The effects of DNase 1 and AAT on NET/MET expression and neutrophil elastase activity were examined in vitro.

Both subject groups had airway neutrophilia with prominent BAL production of NETs with neutrophil elastase co-expression; the mean %±standard error of the mean of neutrophils expressing NETs in the cystic fibrosis group was 23.3±2.8% and in the non-cystic fibrosis group was 28.4±3.9%. NET expression was higher in subjects who had detectable neutrophil elastase activity (p≤0.0074). The percentage of macrophages expressing METs in the cystic fibrosis group was 10.7±1.2% and in the non-cystic fibrosis group was 13.2±1.9%. DNase 1 decreased NET/MET expression (p<0.0001), but increased neutrophil elastase activity (p≤0.0137). The combination of AAT and DNase 1 reduced neutrophil elastase activity (p≤0.0049).

We observed prominent extracellular trap formation in symptomatic children with and without cystic fibrosis. This innate inflammatory response was down-regulated by a combination of currently available therapeutics.

Prominent extracellular trap formation may be observed in young children with airway inflammation, with and without cystic fibrosis. This innate inflammatory response is down-regulated by a combination of currently available therapeutics.https://bit.ly/3bDaWyC

Inhibitory effect of different chicken-derived lactic acid bacteria isolates on drug resistant Salmonella SE47 isolated from eggs

Lactic Acid Bacteria (LAB) regulate and maintain the stability of healthy microbial flora, inhibit the adhesion of pathogenic bacteria and promote the colonization of beneficial micro-organisms. The drug resistance and pathogenicity of Salmonella enteritis SE47 isolated from retail eggs were investigated. Meanwhile, Enterococcus faecalis L76 and Lactobacillus salivarius LAB35 were isolated from intestine of chicken. With SE47 as indicator bacteria, the diameters of L76 and LAB35 inhibition zones were 12 mm and 8·5 mm, respectively, by agar inhibition circle method, which indicated that both of them had inhibitory effect on Salmonella, and L76 had better antibacterial effect; two chicken-derived lactic acid bacteria isolates and Salmonella SE47 were incubated with Caco-2. The adhesion index of L76 was 17·5%, which was much higher than that of LAB35 (10·21%) and SE47 (4·89%), this experiment shows that the higher the bacteriostatic effect of potential probiotics, the stronger the adhesion ability; then Caco-2 cells were incubated with different bacteria, and the survival of Caco-2 cells was observed by flow cytometry. Compared with Salmonella SE47, the results showed that lactic acid bacteria isolates could effectively protect Caco-2 cells; finally, after different bacteria incubated Caco-2 cells, according to the cytokine detection kit, the RNA of Caco-2 cells was extracted and transcribed into cDNA, then detected by fluorescence quantitative PCR, the results showed that L76 could protect Caco-2 cells from the invasion of Salmonella SE47, with less cell membrane rupture and lower expression of MIF and TNF genes. Therefore, the lactic acid bacteria isolates can effectively inhibit the adhesion of Salmonella and protect the integrity of intestinal barrier.

Global FT4 immunoassay standardization: an expert opinion review

OBJECTIVES

Results can vary between different free thyroxine (FT4) assays; global standardization would improve comparability of results between laboratories, allowing development of common clinical decision limits in evidence-based guidelines.

CONTENT

We summarize the path to standardization of FT4 assays, and challenges associated with FT4 testing in special populations, including the need for collaborative efforts toward establishing population-specific reference intervals. The International Federation of Clinical Chemistry and Laboratory Medicine Committee for Standardization of Thyroid Function Tests has undertaken FT4 immunoassay method comparison and recalibration studies and developed a reference measurement procedure that is currently being validated. Further studies are needed to establish common reference intervals/clinical decision limits. Standardization of FT4 assays will change test results substantially; therefore, a major education program will be required to ensure stakeholders are aware of the benefits of FT4 standardization, planned transition procedure, and potential clinical impact of the changes. Assay recalibration by manufacturers and approval process simplification by regulatory authorities will help minimize the clinical impact of standardization.

SUMMARY

Significant progress has been made toward standardization of FT4 testing, but technical and logistical challenges remain.

OUTLOOK

Collaborative efforts by manufacturers, laboratories, and clinicians are required to achieve successful global standardization of the FT4 assays.

Is point of care renal function testing reliable screening pre-IV contrast administration?

PURPOSE

Intravenous iodinated contrast is a commonly used diagnostic aid to improve image quality on computed tomography. There exists a small risk of post-contrast acute kidney injury in patients receiving IV contrast. One of the biggest risk factors for developing PC-AKI is the presence of pre-existing renal dysfunction, making it important to measure the renal function prior to contrast administration. Point of care (POC) devices offer a quick estimation of renal function, potentially improving workflows in radiology departments.

METHOD

Two POC devices were evaluated, the Nova StatSensor and Abbott iSTAT. Patients undergoing routine radiological investigations had blood collected and analysed by a POC method and the laboratory method (Beckman AU5800). The two values were analysed and compared. Renal function was calculated using eGFR via the CKD-EPI result. eGFR values were stratified as high risk (eGFR < 30), moderate risk (eGFR 30-59) and low risk (eGFR ≥ 60).

RESULTS

One hundred eighty-six patients were included in the study. One hundred one patients underwent the Abbott iSTAT analysis, 139 patients underwent Nova StatSensor analysis, and 53 had both. Statistical analysis revealed that the StatSensor R² value was 0.77, and coefficient variation was 10.65%. iSTAT had a R² value of 0.83 and coefficient variation of 7.36%. The POC devices did not miss any high-risk patients but underreported eGFR values in certain patients.

CONCLUSION

POC devices are moderately accurate at detecting renal impairment in patients undergoing radiological investigations. They seem to be a good screening tool; however, any low eGFR values should be further examined.

Cord blood metabolic markers are strong mediators of the effect of maternal adiposity on fetal growth in pregnancies across the glucose tolerance spectrum: the PANDORA study

AIMS/HYPOTHESIS

We aimed to assess associations between cord blood metabolic markers and fetal overgrowth, and whether cord markers mediated the impact of maternal adiposity on neonatal anthropometric outcomes among children born to Indigenous and Non-Indigenous Australian women with normal glucose tolerance (NGT), gestational diabetes mellitus (GDM) and pregestational type 2 diabetes mellitus.

METHODS

From the Pregnancy and Neonatal Outcomes in Remote Australia (PANDORA) study, an observational cohort of 1135 mother-baby pairs, venous cord blood was available for 645 singleton babies (49% Indigenous Australian) of women with NGT (n = 129), GDM (n = 419) and type 2 diabetes (n = 97). Cord glucose, triacylglycerol, HDL-cholesterol, C-reactive protein (CRP) and C-peptide were measured. Multivariable logistic and linear regression were used to assess the associations between cord blood metabolic markers and the outcomes of birthweight z score, sum of skinfold thickness (SSF), being large for gestational age (LGA) and percentage of body fat. Pathway analysis assessed whether cord markers mediated the associations between maternal and neonatal adiposity.

RESULTS

Elevated cord C-peptide was significantly associated with increasing birthweight z score (β 0.57 [95% CI 0.42, 0.71]), SSF (β 0.83 [95% CI 0.41, 1.25]), percentage of body fat (β 1.20 [95% CI 0.69, 1.71]) and risk for LGA [OR 3.14 [95% CI 2.11, 4.68]), after adjusting for age, ethnicity and diabetes type. Cord triacylglycerol was negatively associated with birthweight z score for Indigenous Australian women only. No associations between cord glucose, HDL-cholesterol and CRP >0.3 mg/l (2.9 nmol/l) with neonatal outcomes were observed. C-peptide mediated 18% (95% CI 13, 36) of the association of maternal BMI with LGA and 11% (95% CI 8, 17) of the association with per cent neonatal fat.

CONCLUSIONS/INTERPRETATION

Cord blood C-peptide is an important mediator of the association between maternal and infant adiposity, across the spectrum of maternal glucose tolerance.

Pregnancy And Neonatal Diabetes Outcomes in Remote Australia: the PANDORA study-an observational birth cohort

BACKGROUND

In Australia's Northern Territory, 33% of babies are born to Indigenous mothers, who experience high rates of hyperglycemia in pregnancy. We aimed to determine the extent to which pregnancy outcomes for Indigenous Australian women are explained by relative frequencies of diabetes type [type 2 diabetes (T2DM) and gestational diabetes (GDM)].

METHODS

This prospective birth cohort study examined participants recruited from a hyperglycemia in pregnancy register. Baseline data collected were antenatal and perinatal clinical information, cord blood and neonatal anthropometry. Of 1135 women (48% Indigenous), 900 had diabetes: 175 T2DM, 86 newly diagnosed diabetes in pregnancy (DIP) and 639 had GDM. A group of 235 women without hyperglycemia in pregnancy was also recruited.

RESULTS

Diabetes type differed for Indigenous and non-Indigenous women (T2DM, 36 vs 5%; DIP, 15 vs 7%; GDM, 49 vs 88%, p < 0.001). Within each diabetes type, Indigenous women were younger and had higher smoking rates. Among women with GDM/DIP, Indigenous women demonstrated poorer birth outcomes than non-Indigenous women: large for gestational age, 19 vs 11%, p = 0·002; neonatal fat 11.3 vs 10.2%, p < 0.001. In the full cohort, on multivariate regression, T2DM and DIP were independently associated (and Indigenous ethnicity was not) with pregnancy outcomes.

CONCLUSIONS

Higher rates of T2DM among Indigenous women predominantly contribute to absolute poorer pregnancy outcomes among Indigenous women with hyperglycemia. As with Indigenous and minority populations globally, prevention or delay of type 2 diabetes in younger women is vital to improve pregnancy outcomes and possibly to improve the long-term health of their offspring.

Scale-Dependent Waylaying Effect of Pollinators and Pollination of Mass-Flowering Plants

Pollinators foraging for food resources can be waylaid by mass-flowering plants located in their foraging pathway in landscapes. The waylaying effect of pollinators is often studied at a single spatial scale; to date, little is known about the best spatial extent at which waylaying effect of pollinators can be measured. In this study, we selected a landscape with mass-flowering tufted vetches to determine the spatial scale of waylaying effect of honey bees as well as the consequence of waylaying effect on vetch pollination service. The spatial scale of waylaying effect was determined by the strongest association between honey bee density and distance, selected from a gradient of nested circular buffers centering on apiaries in three different locations. Linear models were used to predict the influence of flower visitor densities on pollination service. For our landscape, honey bee densities were best associated with distances at spatial scales of 500 m, 1150 m, and 1400 m respectively for the three locations of apiaries. Honey bee was the only pollinator whose density displayed a positive relationship with pollination service. At the scales of effect, honey bee density and pollination service declined along the distance. Our findings suggest that the waylaying effect of pollinators needs to be examined at a specific spatial scale and farmers who use honey bees to pollinate their mass-flowering crops need to consider the spatial scale of waylaying effect of pollinators in order to maximize pollination service within agricultural ecosystems.

Composition, physicochemical properties of pea protein and its application in functional foods

Field pea is one of the most important leguminous crops over the world. Pea protein is a relatively new type of plant proteins and has been used as a functional ingredient in global food industry. Pea protein includes four major classes (globulin, albumin, prolamin, and glutelin), in which globulin and albumin are major storage proteins in pea seeds. Globulin is soluble in salt solutions and can be further classified into legumin and vicilin. Albumin is soluble in water and regarded as metabolic and enzymatic proteins with cytosolic functions. Pea protein has a well-balanced amino acid profile with high level of lysine. The composition and structure of pea protein, as well as the processing conditions, significantly affect its physical and chemical properties, such as hydration, rheological characteristics, and surface characteristics. With its availability, low cost, nutritional values and health benefits, pea protein can be used as a novel and effective alternative to substitute for soybean or animal proteins in functional food applications.

Composition, physicochemical properties of pea protein and its application in functional foods

Field pea is one of the most important leguminous crops over the world. Pea protein is a relatively new type of plant proteins and has been used as a functional ingredient in global food industry. Pea protein includes four major classes (globulin, albumin, prolamin, and glutelin), in which globulin and albumin are major storage proteins in pea seeds. Globulin is soluble in salt solutions and can be further classified into legumin and vicilin. Albumin is soluble in water and regarded as metabolic and enzymatic proteins with cytosolic functions. Pea protein has a well-balanced amino acid profile with high level of lysine. The composition and structure of pea protein, as well as the processing conditions, significantly affect its physical and chemical properties, such as hydration, rheological characteristics, and surface characteristics. With its availability, low cost, nutritional values and health benefits, pea protein can be used as a novel and effective alternative to substitute for soybean or animal proteins in functional food applications.

Effects of dietary supplementation of microencapsulated Enterococcus fecalis and the extract of Camellia oleifera seed on laying performance, egg quality, serum biochemical parameters, and cecal microflora diversity in laying hens

The aim of this study was to investigate the effects of microencapsulted Enterococcus faecalis (MEF) and the extract of Camellia oleifera seed (ECOS) on laying performance, serum biochemical parameters, and cecal microflora diversity in laying hens. A total of 180 Hy-Line Brown laying hens, 26-wk-old, were randomly allocated to 6 treatments with 10 replicates and 3 hens per replicate. Dietary treatments were as follows: (A) control group, basal diet; (B) basal diet + 100 mg MEF/kg diet (1 × 1010 cfu/g MEF); (C) basal diet + 300 mg ECOS/kg diet; (D) basal diet + 100 mg MEF/kg diet + 300 mg ECOS/kg diet; (E) basal diet + 500 mg ECOS/kg diet; (F) basal diet + 100 mg MEF/kg diet + 500 mg ECOS/kg diet. The results showed that diets supplemented with MEF and ECOS had no significant effects on laying rate, average egg size, average daily feed intake, feed conversion ratio, eggshell thickness, albumen height, and yolk color (P > 0.05), but had significant effects on egg shape index, eggshell strength, and Haugh unit (P < 0.05) during whole feeding phases. Compared to the control group, the serum IgA and IgG levels of birds in Group F significantly increased (P < 0.05). The serum total cholesterol, low-density lipoprotein cholesterol, total triglyceride, and blood urea nitrogen levels of birds in Group D and Group F significantly reduced (P < 0.05), and the high-density lipoprotein cholesterol level of birds in Group D and Group F significantly increased (P < 0.05). At the phylum level, Firmicutes decreased (P < 0.05) and Bacteroidetes increased (P < 0.05) in the birds of Group D. Ruminococcus and Bacteroides were significantly affected by dietary treatments (P < 0.05), and Bacteroides in the birds of Group D significantly increased at the genus level. Therefore, diet supplemented with MEF and ECOS can significantly improve serum biochemical parameters and increase cecal microflora diversity.

The stability and variability of serum and plasma fibroblast growth factor-23 levels in a haemodialysis cohort

Background

Serum fibroblast growth factor 23 (FGF-23) levels are markedly elevated in haemodialysis patients and have been linked to mortality outcomes. Small studies in health and chronic kidney disease, have demonstrated marked intra- and inter-individual variability in measured FGF-23 levels, and variable degradation in serum as compared to plasma samples. In end-stage kidney disease (ESKD), the intra- and inter-individual variability of FGF-23 levels, and the optimal collection methods remain poorly characterized. In this study we assessed the variability of FGF-23 levels in a cohort of stable haemodialysis patients. Secondly, in a subset of patients, we assessed the effects of different collection methods on measured FGF-23 levels.

Methods

To assess the variability of FGF-23, pre-dialysis blood samples were collected over 3 consecutive weeks from 75 haemodialysis patients. The effects of different specimen collection methods were examined in a subset of patients (n = 23), with pre-dialysis blood collected into different tubes: plain (serum), EDTA (plasma) and EDTA with the addition of a protease inhibitor (EDTA-PI). All analyses were performed in the main cohort and repeated in each subgroup. Variability over a 3-week period was assessed using repeated measures ANOVA and random effects linear regression models. Intra-class correlation coefficients were calculated to assess agreement, and coefficients of variation were calculated to assess intra- and inter-individual variability.

Results

Over the 3-week study period the mean FGF-23 levels were not significantly different in the serum (p = 0.26), EDTA (p = 0.62) and EDTA-PI (p = 0.55) groups. FGF-23 levels demonstrated marked intra- and inter-individual variability with a CV of 36 and 203.2%, respectively. In the subgroup analysis, the mean serum FGF-23 levels were significantly lower than the EDTA (p < 0.001) or EDTA-PI (p < 0.001) groups, however there was no difference in mean FGF-23 levels between EDTA and EDTA-PI (p = 0.54).

Conclusions

The measured FGF-23 levels were significantly lower in serum as compared to plasma, and the addition of a protease inhibitor did not confer an additional benefit. Importantly in this cohort of ESKD patients, FGF-23 levels showed marked intra- and inter-individual variability. The routine measurement of FGF-23 in ESKD remains challenging, however this study suggests the plasma is the optimal collection method for FGF-23 analysis.

Reference intervals for neonatal thyroid function tests in the first 7 days of life

BACKGROUND

Prompt intervention can prevent permanent adverse neurological effects caused by neonatal hypothyroidism. Thyroid function changes rapidly in the first few days of life but well-defined age-specific reference intervals (RIs) for thyroid-stimulating hormone (TSH), free thyroxine (FT4) and free tri-iodothyronine (FT3) are not available to aid interpretation. We developed hour-based RIs using data mining.

METHODS

All TSH, FT4 and FT3 results with date and time of collection from neonates aged <7 days during 2005-2015 were extracted from the Monash Pathology database. Neonates with more than one episode of testing or with known primary hypothyroidism, identified by treating physicians or from medical records, were excluded from the analysis. The date and time of birth were obtained from the medical records.

RESULTS

Of the 728 neonates qualifying for the study, 569 had time of birth available. All 569 had TSH, 415 had FT4 and 146 had FT3 results. For age ≤24 h, 25-48 h, 49-72 h, 73-96 h, 97-120 h, 121-144 h and 145-168 h of life, the TSH RIs (2.5th-97.5th) (mIU/L) were 4.1-40.2, 3.2-29.6, 2.6-17.3, 2.2-14.7, 1.8-14.2, 1.4-12.7 and 1.0-8.3, respectively; the FT4 RIs (mean ± 2 standard deviation [SD]) (pmol/L) were 15.3-43.6, 14.7-53.2, 16.5-45.5, 17.8-39.4, 15.3-32.1, 14.5-32.6 and 13.9-30.9, respectively; the FT3 RIs (mean±2 SD) (pmol/L) were 5.0-9.4, 4.1-9.1, 2.8-7.8, 2.9-7.8, 3.5-7.2, 3.4-8.0 and 3.8-7.9, respectively.

CONCLUSIONS

TSH and FT4 were substantially high in the first 24 h after birth followed by a rapid decline over the subsequent 168 h. Use of hour-based RIs in newborns allows for more accurate identification of neonates who are at risk of hypothyroidism.

Higher maternal serum prolactin levels are associated with reduced glucose tolerance during pregnancy

It is unknown if high prolactin levels during pregnancy contribute to the development of gestational diabetes. We hypothesized that higher prolactin levels are associated with reduced glucose tolerance, as determined by higher 2-h glucose level from an oral glucose tolerance test in pregnancy. The 75-g oral glucose tolerance test was carried out at 28 weeks of gestation in 69 participants. A multiple regression analysis was used to determine the relationship between serum prolactin and 2-h glucose levels. Multivariable regression analysis showed an independent and significant relationship between third trimester prolactin and 2-h glucose levels post oral glucose tolerance test. Higher prolactin levels were associated with higher glucose levels independent of age, body mass index, gravidity and parity. Higher prolactin levels associated with reduced glucose tolerance in the third trimester of pregnancy suggests the possible independent role of prolactin in the pathogenesis of gestational diabetes.

Harmonisation of Osmolal Gap - Can We Use a Common Formula?

Osmolal gap is the difference between the measured osmolality and a calculated osmolality based on the major commonly measured osmotically active particles. The perceived gap indicates the presence of unmeasured osmotically active particles. The major use of osmolal gap today is to screen for the possible presence of exogenous toxic substances in patients in an emergency department or intensive care unit. There is a long history of osmolal gap calculations and it needs to be appreciated that the uncertainty of the osmolal gap will be determined by the sum of errors in the calculated osmolality, error in measured osmolality and variability in unmeasured analytes. Since 1958 there has been a constant trickle of papers proposing both simple and sophisticated formulae to calculate the 'ultimate' osmolal gap. A gap as close to zero as possible and with a low coefficient of variation across multiple clinical conditions and analytical platforms are also determinants of 'fitness for purpose' of any osmolal gap calculations. The Smithline-Gardner formula for calculated osmolality [2(Na) + Glu + Urea] is fit for purpose in both normal people and general hospital patients. It also performs well across different analytical platforms. This simple formula can be used for rapid mental calculation at the bedside and automated laboratory information system reporting whenever a measured osmolality is requested. In this era of harmonisation, we propose that this formula be adopted by all clinicians and laboratories.

Cystatin C estimated glomerular filtration rate and all-cause and cardiovascular disease mortality risk in the general population: AusDiab study

AIMS

Uncertainties about the role of cystatin C-based estimated glomerular filtration rate (eGFR) in the prediction of cardiovascular disease (CVD) beyond traditional CVD risk factors remain. We assessed contributions of eGFR to CVD and mortality in the general population.

METHODS

Using 14 year follow-up data on 9353 adults without a reported history of CVD from the Australian Diabetes, Obesity and Lifestyle study, we assessed the contributions of eGFR (assessed by cystatin C (eGFR_cysC ) and serum creatinine (eGFR_cr ) and albuminuria (uACR) to total and CVD mortality.

RESULTS

After adjusting for age, sex, CVD risk factors and uACR, compared with an eGFR_cysC >90 mL/min per 1.73 m² , eGFR_cysC <60 mL/min per 1.73 m² was associated with 56% and 73% increases in the risks for all-cause and CVD mortality, respectively. The respective changes for the c-statistic when eGFR_cysC was added to a risk prediction model were 0.003 (95% confidence interval: 0.001 to 0.005) and 0.002 (95% confidence interval: -0.001 to 0.006). The net proportion of non-events assigned a lower-risk category significantly improved with the addition of eGFR (non-event net reclassification index eGFR_cr : 1.0% and eGFR_cysC : 1.5%) for all-cause mortality, but for CVD mortality, improvements were only significant when eGFR was combined with uACR. The net proportion of events assigned a higher-risk category was not significantly improved.

CONCLUSION

In our community-based cohort, reduced eGFR_cysC was associated with all-cause and CVD mortality. The addition of chronic kidney disease measures to risk prediction models improved overall risk stratification among those at low risk as opposed to those at high baseline risk of mortality.

The Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equation does not improve the underestimation of Glomerular Filtration Rate (GFR) in people with diabetes and preserved renal function

BACKGROUND

Our hypothesis was that both the Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) and Modification of Diet in Renal Disease (MDRD) equations would underestimate directly measured GFR (mGFR) to a similar extent in people with diabetes and preserved renal function.

METHODS

In a cross-sectional study, bias (eGFR - mGFR) was compared for the CKD-EPI and MDRD equations, after stratification for mGFR levels. We also examined the ability of the CKD-EPI compared with the MDRD equation to correctly classify subjects to various CKD stages. In a longitudinal study of subjects with an early decline in GFR i.e., initial mGFR > 60 ml/min/1.73 m(2) and rate of decline in GFR (ΔmGFR) > 3.3 ml/min/1.73 m(2) per year, ΔmGFR (based on initial and final values) was compared with ΔeGFR by the CKD-EPI and MDRD equations over a mean of 9 years.

RESULTS

In the cross-sectional study, mGFR for the whole group was 80 ± 2.2 ml/min/1.73 m(2) (n = 199, 75 % type 2 diabetes). For subjects with mGFR >90 ml/min/1.73 m(2) (mGFR: 112 ± 2.0, n = 76), both equations significantly underestimated mGFR to a similar extent: bias for CKD-EPI: -12 ± 1.4 ml/min/1.73 m(2) (p < 0.001) and for MDRD: -11 ± 2.1 ml/min/1.73 m(2) (p < 0.001). Using the CKD-EPI compared with the MDRD equation did not improve the number of subjects that were correctly classified to a CKD-stage. No biochemical or clinical patient characteristics were identified to account for the under estimation of mGFR values in the normal to high range by the CKD-EPI equation. In the longitudinal study (n = 30, 66 % type 1 diabetes), initial and final mGFR values were 102.8 ± 6 and 54.6 ± 6.0 ml/min/1.73 m(2), respectively. Mean ΔGFR (ml/min/1.73 m(2) per year) was 6.0 by mGFR compared with only 3.0 by MDRD and 3.2 by CKD-EPI (both p < 0.05 vs mGFR) CONCLUSIONS: Both the CKD-EPI and MDRD equations underestimate reference GFR values > 90 ml/min/1.73 m(2) as well as an early decline in GFR to a similar extent in people with diabetes. There is scope to improve methods for estimating an early decline in GFR.

The Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equation does not improve the underestimation of Glomerular Filtration Rate (GFR) in people with diabetes and preserved renal function

Background

Our hypothesis was that both the Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) and Modification of Diet in Renal Disease (MDRD) equations would underestimate directly measured GFR (mGFR) to a similar extent in people with diabetes and preserved renal function.

Methods

In a cross-sectional study, bias (eGFR – mGFR) was compared for the CKD-EPI and MDRD equations, after stratification for mGFR levels. We also examined the ability of the CKD-EPI compared with the MDRD equation to correctly classify subjects to various CKD stages. In a longitudinal study of subjects with an early decline in GFR i.e., initial mGFR >60 ml/min/1.73 m² and rate of decline in GFR (ΔmGFR) > 3.3 ml/min/1.73 m² per year, ΔmGFR (based on initial and final values) was compared with ΔeGFR by the CKD-EPI and MDRD equations over a mean of 9 years.

Results

In the cross-sectional study, mGFR for the whole group was 80 ± 2.2 ml/min/1.73 m² (n = 199, 75 % type 2 diabetes). For subjects with mGFR >90 ml/min/1.73 m² (mGFR: 112 ± 2.0, n = 76), both equations significantly underestimated mGFR to a similar extent: bias for CKD-EPI: -12 ± 1.4 ml/min/1.73 m² (p < 0.001) and for MDRD: -11 ± 2.1 ml/min/1.73 m² (p < 0.001). Using the CKD-EPI compared with the MDRD equation did not improve the number of subjects that were correctly classified to a CKD-stage. No biochemical or clinical patient characteristics were identified to account for the under estimation of mGFR values in the normal to high range by the CKD-EPI equation. In the longitudinal study (n = 30, 66 % type 1 diabetes), initial and final mGFR values were 102.8 ± 6 and 54.6 ± 6.0 ml/min/1.73 m², respectively. Mean ΔGFR (ml/min/1.73 m² per year) was 6.0 by mGFR compared with only 3.0 by MDRD and 3.2 by CKD-EPI (both p < 0.05 vs mGFR)

Conclusions

Both the CKD-EPI and MDRD equations underestimate reference GFR values >90 ml/min/1.73 m² as well as an early decline in GFR to a similar extent in people with diabetes. There is scope to improve methods for estimating an early decline in GFR.

Bacillus amyloliquefaciens supplementation alleviates immunological stress in lipopolysaccharide-challenged broilers at early age

This study was conducted to investigate the effect of Bacillus amyloliquefaciens ( BA: ) on the immune function of broilers challenged with lipopolysaccharide ( LPS: ). 192 one-day-old male Arbor Acre broiler chickens were randomly distributed into four treatments: 1) broilers fed a basal diet; 2) broilers fed a basal diet supplemented with BA; 3) LPS-challenged broilers fed a basal diet; and 4) LPS-challenged broilers fed a basal diet supplemented with BA. Each treatment consisted of six replicates with eight broilers per replicate. Broilers were intraperitoneally injected with either 500 μg LPS per kg body weight or sterile saline at 16, 18 and 20 d of age. LPS decreased the average daily gain ( ADG: , P = 0.001) and average daily feed intake (P = 0.001). The decreased ADG (P = 0.009) and increased feed conversion ratio (P = 0.047) in LPS-challenged broilers were alleviated by BA. LPS increased the relative spleen weight (P = 0.001). Relative spleen (P = 0.014) and bursa (P = 0.024) weights in the LPS-challenged broilers were reduced by BA. LPS increased white blood cell ( WBC: ) numbers (P = 0.001). However, the WBC numbers (P = 0.042) and the ratio of lymphocytes to WBC (P = 0.020) in LPS-challenged broilers were decreased with BA treatment. LPS decreased plasma lysozyme activity (P = 0.001), but increased concentrations of plasma corticosterone (P = 0.012) and IL-2 (P = 0.020). In contrast, BA increased lysozyme activity in plasma (P = 0.040). LPS increased mRNA abundances of splenic toll-like receptor 4 (P = 0.046), interferon γ (P = 0.008), IL-1β (P = 0.045) and IL-6, (P = 0.006). IL-2 (P = 0.014) and IL-6 (P = 0.074) mRNA abundances in LPS-challenged broilers were reduced by BA, although BA had an opposite effect for IL-10 mRNA expression in those broilers (P = 0.004). In conclusion, BA supplementation could partially alleviate the compromised growth performance and immune status of broilers under immune stress induced by LPS challenge at early age.

A longitudinal study of thyroid autoantibodies in pregnancy: the importance of test timing

OBJECTIVE

Thyroid peroxidase antibodies (TPOAb) and thyroglobulin antibodies (TGAb) are frequently measured to investigate thyroid dysfunction in pregnancy. Despite the recognized fall of these autoantibodies in pregnancy, there is limited guidance on the timing of such testing. We assessed optimal test timing of TPOAb/TGAb for the detection of Hashimoto's thyroiditis and post-partum thyroid dysfunction (PPTD).

DESIGN

Prospective longitudinal study with recruitment in Trimester 1.

PATIENTS

Healthy women ≤13 weeks' gestation from Mercy Hospital for Women, a tertiary obstetric hospital in Melbourne.

MEASUREMENTS

Serum TPOAb, TGAb, TSH and fT4 were measured at Trimester 1 (T1), Trimester 2(T2), Trimester 3(T3) and postpartum (PP) in each participant. Post-partum thyroid dysfunction (PPTD) was defined if TSH deviated from the assay's nonpregnant reference interval. Longitudinal random-effect logistic regression was used to investigate the association between time and positive/negative thyroid autoantibody status.

RESULTS

Samples from 140 women at T1 (12·0: 10·3-13·0) (median: IQR weeks' gestation); 95 at T2 (24·3: 23·0-25·9), 79 at T3 (35·9: 34·8-36·7) and 83 at PP (12·4: 10·8-14·6 weeks post-partum) were attained. At T1, 13 (9%) and 15 (11%) women had positive TPOAb and TGAb, respectively. The odds of having a positive TPOAb were 96% lower at T2 [OR = 0·04 (95% CI: 0·02-0·8; P = 0·03)] and 97% lower at T3 [OR = 0·03 (95% CI: 0·001-0·6; P = 0·02)] than at T1. Similarly, the odds of having a positive TGAb were 99·4% lower [OR = 0·006 (95% CI: 0-0·3; P = 0·01)] at T2, and 99·5% lower [OR = 0·005 (95% CI: 0-0·4; P = 0·02)] at T3 than at T1. The ROC analysis diagnostic ORs for a positive TPOAb and/or TGAb to predict PPTD were 7·8 (95% CI: 2·2-27·6), 1·2 (95% CI: 0-8·9), 2·0 (95% CI: 0-16·8), and 12·2 (95% CI: 3·3-44·9) at T1, T2, T3 and post-partum, respectively.

CONCLUSIONS

A significant proportion of pregnant women lose their thyroid autoantibody positivity after T1. The gestation-dependent loss of TPOAb/TGAb positivity and reduction in diagnostic accuracy for predicting PPTD limits the value of testing at T2 and T3.

Effects of combined calcium and vitamin D supplementation on insulin secretion, insulin sensitivity and β-cell function in multi-ethnic vitamin D-deficient adults at risk for type 2 diabetes: a pilot randomized, placebo-controlled trial

OBJECTIVES

To examine whether combined vitamin D and calcium supplementation improves insulin sensitivity, insulin secretion, β-cell function, inflammation and metabolic markers.

DESIGN

6-month randomized, placebo-controlled trial.

PARTICIPANTS

Ninety-five adults with serum 25-hydroxyvitamin D [25(OH)D] ≤55 nmol/L at risk of type 2 diabetes (with prediabetes or an AUSDRISK score ≥15) were randomized. Analyses included participants who completed the baseline and final visits (treatment n = 35; placebo n = 45).

INTERVENTION

Daily calcium carbonate (1,200 mg) and cholecalciferol [2,000-6,000 IU to target 25(OH)D >75 nmol/L] or matching placebos for 6 months.

MEASUREMENTS

Insulin sensitivity (HOMA2%S, Matsuda index), insulin secretion (insulinogenic index, area under the curve (AUC) for C-peptide) and β-cell function (Matsuda index x AUC for C-peptide) derived from a 75 g 2-h OGTT; anthropometry; blood pressure; lipid profile; hs-CRP; TNF-α; IL-6; adiponectin; total and undercarboxylated osteocalcin.

RESULTS

Participants were middle-aged adults (mean age 54 years; 69% Europid) at risk of type 2 diabetes (48% with prediabetes). Compliance was >80% for calcium and vitamin D. Mean serum 25(OH)D concentration increased from 48 to 95 nmol/L in the treatment group (91% achieved >75 nmol/L), but remained unchanged in controls. There were no significant changes in insulin sensitivity, insulin secretion and β-cell function, or in inflammatory and metabolic markers between or within the groups, before or after adjustment for potential confounders including waist circumference and season of recruitment. In a post hoc analysis restricted to participants with prediabetes, a significant beneficial effect of vitamin D and calcium supplementation on insulin sensitivity (HOMA%S and Matsuda) was observed.

CONCLUSIONS

Daily vitamin D and calcium supplementation for 6 months may not change OGTT-derived measures of insulin sensitivity, insulin secretion and β-cell function in multi-ethnic adults with low vitamin D status at risk of type 2 diabetes. However, in participants with prediabetes, supplementation with vitamin D and calcium may improve insulin sensitivity.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ACTRN12609000043235.

Serum vitamin D levels, diabetes and cardio-metabolic risk factors in Aboriginal and Torres Strait Islander Australians

BACKGROUND

Low levels of serum 25-hydroxy vitamin D (25(OH)D), have been associated with development of type 2 diabetes and cardiovascular disease (CVD); however there are limited data on serum 25(OH)D in Indigenous Australians, a population at high risk for both diabetes and CVD. We aimed to assess levels of serum 25(OH)D in Aboriginal and Torres Strait Islander Australians and to explore relationships between 25(OH)D and cardio-metabolic risk factors and diabetes.

METHODS

592 Aboriginal and/or Torres Strait Islander Australian participants of The eGFR (estimated glomerular filtration rate) Study, a cross-sectional analysis of a cohort study performed in 2007-2011, from urban and remote centres within communities, primary care and tertiary hospitals across Northern Territory, Far North Queensland and Western Australia. Assessment of serum 25(OH)D, cardio-metabolic risk factors (central obesity, diabetes, hypertension, history of cardiovascular disease, current smoker, low HDL-cholesterol), and diabetes (by history or HbA1c ≥6.5%) was performed. Associations were explored between 25(OH)D and outcome measures of diabetes and number of cardio-metabolic risk factors.

RESULTS

The median (IQR) serum 25(OH)D was 60 (45-77) nmol/L, 31% had 25(OH)D <50 nmol/L. For participants with 25(OH)D < 50 vs ≥50 nmol/L, cardio-metabolic risk profile differed for: diabetes (54%, 36% p < 0.001), past history of cardiovascular disease (16%, 9%, p = 0.014), waist-hip ratio (0.98, 0.92, p < 0.001), urine albumin-creatinine ratio (2.7, 1.5 mg/mmol, p < 0.001). The OR (95% CI) for diabetes was 2.02 (1.03 - 3.95) for people in the lowest vs highest tertiles of 25(OH)D (<53 vs >72 nmol/L, respectively) after adjusting for known cardio-metabolic risk factors.

CONCLUSION

The percentage of 25(OH)D levels <50 nmol/L was high among Aboriginal and Torres Strait Islander Australians from Northern and Central Australia. Low 25(OH)D level was associated with adverse cardio-metabolic risk profile and was independently associated with diabetes. These findings require exploration in longitudinal studies.

Association of sedentary behaviour with colon and rectal cancer: a meta-analysis of observational studies

BACKGROUND

Sedentary behaviour is ubiquitous in modern society. Emerging studies have focused on the health consequences of sedentary behaviour, including colorectal cancer, but whether sedentary behaviour is associated with the risks of colon and rectal cancer remains unclear. No systematic reviews have applied quantitative techniques to independently compute summary risk estimates. We aimed to conduct a meta-analysis to investigate this issue.

METHODS

We searched PubMed, Embase, and Google Scholar databases up to May 2013 to identify cohort and case-control studies that evaluated the association between sedentary behaviour and colon or rectal cancer. A random-effect model was used to pool the results of included studies. Publication bias was assessed by using Begg's funnel plot.

RESULTS

Twenty-three studies with 63 reports were included in our meta-analysis. These groups included 4,324,462 participants (27,231 colon cancer cases and 13,813 rectal cancer cases). Sedentary behaviour was significantly associated with colon cancer (relative risk (RR): 1.30, 95% confidence interval (CI): 1.22-1.39) but did not have a statistically significant association with rectal cancer (RR 1.05, 95% CI, 0.98-1.13). Subgroup analyses suggested that the odds ratio (OR) of colon cancer was 1.46 (95% CI: 1.22-1.68) in the case-control studies, and the RR was 1.27 (95% CI: 1.18-1.36) in the cohort studies, the OR of rectal cancer was 1.06 (95% CI: 0.85-1.33) in the case-control studies, and the RR was 1.06 (95% CI, 1.01-1.12) in the cohort studies.

CONCLUSION

Sedentary behaviour is associated with an increased risk of colon cancer. Subgroup analyses suggest a positive association between sedentary behaviour and risk of rectal cancer in cohort studies. Reducing sedentary behaviour is potentially important for the prevention of colorectal cancer.

Longitudinal assessment of thyroid function in pregnancy

Background

Trimester-specific reference intervals (RIs) for thyroid function tests are lacking for Beckman Dxl 800 analysers. We aimed to establish RIs for thyroid stimulating hormone (TSH), free thyroxine (fT4) and to track intraindividual changes in thyroid function throughout pregnancy.

Methods

One hundred and thirty healthy women without antithyroid peroxidase antibodies were followed longitudinally. Thyroid function was determined at trimester-1 (T1): 9–13 weeks; trimester-2 (T2): 22–26 weeks; trimester-3 (T3): 35–39 weeks and postpartum (PP): 8–12 weeks. A subgroup ( n = 47) was used to track intraindividual changes using PP as non-pregnant state (baseline).

Results

For trimesters 1–3, TSH (median (2.5th, 5th, 95th and 97.5th percentile)) was 0.77 (0.03, 0.05, 2.33, 3.05), 1.17 (0.42, 0.47, 2.71, 3.36) and 1.35 (0.34, 0.42, 2.65, 2.83) mIU/L, respectively. Free T4 (mean (95%CI)) was 10.7 (5.9–15.5), 8.1 (4.9–11.3), 7.8 (4.5–11.0) pmol/L, respectively. In T2 and T3, 36% and 41% of the fT4 values, respectively, fell below the non-pregnancy lower normal limit. In the subgroup assessed for longitudinal changes, of the women with baseline TSH ⩽ median, 71–75% remained at or below the corresponding median for trimesters 1–3. Of the women with baseline fT4 ⩽ median, 69–81% also remained at or below the corresponding median for trimesters 1–3. High correlation was observed at different trimesters and baseline for TSH (Spearman’s r: 0.593–0.846, P < 0.001) and for fT4 ( r: 0.480–0.739, P < 0.001).

Conclusions

Use of trimester-specific RIs would prevent misclassification of thyroid function during pregnancy. In the majority of women, TSH and fT4 tracked on the same side of the median distribution, from a non-pregnant baseline, throughout pregnancy.

Vitamin B12 and homocysteine status during pregnancy in the metformin in gestational diabetes trial: responses to maternal metformin compared with insulin treatment

AIM

The aim of the study is to compare the effects of metformin and insulin treatment for gestational diabetes mellitus (GDM) on vitamin B12 and homocysteine (Hcy) status.

METHODS

Women with GDM, who met criteria for insulin treatment, were randomly assigned to metformin (n = 89) or insulin (n = 91) in the Adelaide cohort of the metformin in gestational diabetes (MiG) trial. Fasting serum total vitamin B12 (TB12), holotranscobalamin (HoloTC), a marker of functional B12 status and plasma Hcy concentrations were measured at 20-34 weeks (at randomization) and 36 weeks gestation, then at 6-8 weeks postpartum.

RESULTS

Circulating TB12, HoloTC and Hcy were similar in both treatment groups at each time point. Women who were taking dietary folate supplements at randomization had higher serum TB12 and HoloTC at randomization than those not taking folate. Overall, serum TB12 fell more between randomization and 36 weeks gestation in the metformin group than in the insulin group (metformin: -19.7 ± 4.7 pmol/l, insulin: -6.4 ± 3.6 pmol/l, p = 0.004). The decrease in serum TB12 during treatment was greater with increasing treatment duration in metformin-treated (p < 0.001), but not in insulin-treated women.

CONCLUSIONS

Total, but not bioavailable, vitamin B12 stores were depleted during pregnancy to a greater extent in metformin-treated than in insulin-treated women with GDM, but neither analyte differed between groups at any stage. This adds further evidence supporting metformin as a safe alternative treatment to insulin in GDM. Further investigation is needed to evaluate whether women treated with metformin for longer periods in pregnancy require additional B12 or other supplementation.

25-Hydroxyvitamin D levels and chronic kidney disease in the AusDiab (Australian Diabetes, Obesity and Lifestyle) study

Background

Low 25-hydroxy vitamin D (25(OH)D) levels have been associated with an increased risk of albuminuria, however an association with glomerular filtration rate (GFR) is not clear. We explored the relationship between 25(OH)D levels and prevalent chronic kidney disease (CKD), albuminuria and impaired GFR, in a national, population-based cohort of Australian adults (AusDiab Study).

Methods

10,732 adults ≥25 years of age participating in the baseline survey of the AusDiab study (1999–2000) were included. The GFR was estimated using an enzymatic creatinine assay and the CKD-EPI equation, with CKD defined as eGFR <60 ml/min/1.73 m². Albuminuria was defined as a spot urine albumin to creatinine ratio (ACR) of ≥2.5 mg/mmol for men and ≥3.5 for women. Serum 25(OH)D levels of <50 nmol/L were considered vitamin D deficient. The associations between 25(OH)D level, albuminuria and impaired eGFR were estimated using multivariate regression models.

Results

30.7% of the study population had a 25(OH)D level <50 nmol/L (95% CI 25.6-35.8). 25(OH)D deficiency was significantly associated with an impaired eGFR in the univariate model (OR 1.52, 95% CI 1.07-2.17), but not in the multivariate model (OR 0.95, 95% CI 0.67-1.35). 25(OH)D deficiency was significantly associated with albuminuria in the univariate (OR 2.05, 95% CI 1.58-2.67) and multivariate models (OR 1.54, 95% CI 1.14-2.07).

Conclusions

Vitamin D deficiency is common in this population, and 25(OH)D levels of <50 nmol/L were independently associated with albuminuria, but not with impaired eGFR. These associations warrant further exploration in prospective and interventional studies.

Prevalence of vitamin D deficiency and its determinants in Australian adults aged 25 years and older: a national, population-based study

OBJECTIVE

Vitamin D deficiency is recognized as a global public health problem, but the population-based prevalence of deficiency and its determinants in Australian adults is not known. This study evaluated the vitamin D status of Australian adults aged ≥25 years and risk factors associated with vitamin D deficiency in this population.

DESIGN AND PATIENTS

We studied a national sample of 11,247 Australian adults enrolled in the 1999/2000 Australian Diabetes, Obesity and Lifestyle (AusDiab) study drawn from 42 randomly selected districts throughout Australia.

MEASUREMENTS

Serum concentrations of 25-hydroxyvitamin D [25(OH)D] were measured by immunoassay. Vitamin D deficiency was defined as a concentration <50 nmol/l. Information on demographic and lifestyle factors was derived from interview-administered questionnaires.

RESULTS

The mean serum 25(OH)D concentration was 63 nmol/l (95% CI: 59-67 nmol/l). Only 4% of the population had a level <25 nmol/l, but the prevalence of vitamin D deficiency (<50 nmol/l) was 31% (22% men; 39% women); 73% had levels <75 nmol/l. The prevalence of vitamin D deficiency increased significantly with age, was greater in women, in those of non-Europid origin, in the obese and those who were physically inactive and with a higher level of education. Deficiency was also more common during winter and in people residing in southern Australia (latitude >35°S); 42% of women and 27% of men were deficient during summer-autumn, which increased to 58% and 35%, respectively, during winter-spring.

CONCLUSION

Vitamin D deficiency is common in Australia affecting nearly one-third of adults aged ≥25 years. This indicates that strategies are needed at the population level to improve vitamin D status of Australians.

Low serum 25-hydroxyvitamin D is associated with increased risk of the development of the metabolic syndrome at five years: results from a national, population-based prospective study (The Australian Diabetes, Obesity and Lifestyle Study: AusDiab)

CONTEXT

Serum 25-hydroxyvitamin D [25(OH)D] concentration has been inversely associated with the prevalence of metabolic syndrome (MetS), but the relationship between 25(OH)D and incident MetS remains unclear.

OBJECTIVE

We evaluated the prospective association between 25(OH)D, MetS, and its components in a large population-based cohort of adults aged 25 yr or older.

DESIGN

We used baseline (1999-2000) and 5-yr follow-up data of the Australian Diabetes, Obesity, and Lifestyle Study (AusDiab).

PARTICIPANTS

Of the 11,247 adults evaluated at baseline, 6,537 returned for follow-up. We studied those without MetS at baseline and with complete data (n = 4164; mean age 50 yr; 58% women; 92% Europids).

OUTCOME MEASURES

We report the associations between baseline 25(OH)D and 5-yr MetS incidence and its components, adjusted for age, sex, ethnicity, season, latitude, smoking, family history of type 2 diabetes, physical activity, education, kidney function, waist circumference (WC), and baseline MetS components.

RESULTS

A total of 528 incident cases (12.7%) of MetS developed over 5 yr. Compared with those in the highest quintile of 25(OH)D (≥34 ng/ml), MetS risk was significantly higher in people with 25(OH)D in the first (<18 ng/ml) and second (18-23 ng/ml) quintiles; odds ratio (95% confidence interval) = 1.41 (1.02-1.95) and 1.74 (1.28-2.37), respectively. Serum 25(OH)D was inversely associated with 5-yr WC (P < 0.001), triglycerides (P < 0.01), fasting glucose (P < 0.01), and homeostasis model assessment for insulin resistance (P < 0.001) but not with 2-h plasma glucose (P = 0.29), high-density lipoprotein cholesterol (P = 0.70), or blood pressure (P = 0.46).

CONCLUSIONS

In Australian adults, lower 25(OH)D concentrations were associated with increased MetS risk and higher WC, serum triglyceride, fasting glucose, and insulin resistance at 5 yr. Vitamin D supplementation studies are required to establish whether the link between vitamin D deficiency and MetS is causal.

Effects of Cu underlayer on the growth and magnetic properties of FePt thin films on MgO (001) substrate

During ordering process of face centered tegragonal (fct) L1(0) phase of the FePt alloy, there exist three growth variants of axes (001) from original disordered fcc structured phase. When FePt film was directly deposited on the MgO (001) substrate, the variant perpendicular to the film plane grew, resulting in a low out-of-plane coercivity of 1.3 kOe. By using Cu underlayer, two variants lying in the film plane got same chance to grow, which caused an in-plane perpendicular alignment of the tetragonal axes of FePt L1(0) phases. The crystallographic relationship between Cu and FePt layers is Cu (100)<100>//fct FePt (100)<100>. A high in-plane coercivity of 4.6 kOe was obtained due to the high density of micro-defects (mcro-twins, anti-phase boundaries, etc.) in the film plane. This work demonstrated a way of selecting the growth variants of ordering process to adjust the magnetic properties of the ordered FePt thin films.