People with type 2 diabetes have increased fracture risk despite preserved bone density. In this matched cross-sectional study, suppressed Bone Status Indices and exploratory sex-related hormonal associations were observed in T2D, indicating altered bone remodeling that is not captured by aBMD alone. These findings support the need for fracture risk assessment approaches that incorporate biochemical markers and potential sex-related differences. People with type 2 diabetes (T2D) experience increased fracture risk despite preserved or higher areal bone mineral density (aBMD). We evaluated Bone Status Indices (BSIs) and their relationships with aBMD in T2D, with exploratory evaluation of sex-related hormonal influences. In this matched cross-sectional study from the DiaFALL cohort, 105 adults with T2D were compared 1:1 with age- and sex-matched controls. aBMD was assessed at lumbar spine, femoral neck, arms, and legs using DXA. BSIs included intact PINP (i-PINP), β-CTX-I, osteocalcin (OCN), sclerostin, TRACP5b, IGF-1, OPN, PTH, and vitamin-D metabolites. Group differences and associations with aBMD were evaluated using multivariable regression and Spearman correlations, with exploratory sex-stratified analyses. Femoral-neck aBMD was higher in people with T2D (men: + 0.070 g/cm2, 95

INTRODUCTION/AIM:This study investigated differences in bone turnover markers (BTMs) and their associations with areal bone mineral density (aBMD) in people with type 1 diabetes (T1D) to better understand the mechanisms underlying skeletal fragility, including sex- and hormone-related variations. METHODS:A cohort of 110 Caucasian participants with T1D were matched 1: 1 with age- and sex-matched controls. aBMD at the lumbar spine, femoral neck, legs, and arms was assessed using DXA. BTMs included P1NP, osteocalcin (OC), sclerostin, CTX-1, TRAcP, IGF-1, BASP, and osteopontin (OPN). Group comparisons were conducted using t-tests, and associations between BTMs and aBMD were examined using regression and Spearman correlations. Exploratory subgroup analyses stratified women by menopausal status. RESULTS:Bone formation markers (P1NP, OC) were significantly lower in T1D men compared to controls (P1NP: p = 0.046; OC: p = 0.002), reflecting suppressed bone formation. IGF-1 was reduced in both sexes (p < 0.001) and correlated positively with aBMD in women (p < 0.05), but not in men. Sclerostin levels were elevated in both sexes (p = 0.002-<0.001) without correlating with aBMD. CTX-1 was reduced in T1D men (p = 0.004), while TRAcP was elevated in both sexes (p = 0.044), correlating negatively with aBMD in women. Men with T1D had significantly lower leg aBMD (p = 0.032) and reduced femoral neck bone mineral content (p = 0.041). No overall differences were observed among women; however, exploratory analyses revealed that postmenopausal women with T1D had higher TRAcP and sclerostin levels and lower femoral neck aBMD compared to premenopausal counterparts. CONCLUSION:T1D was associated with significant alterations in certain BTMs and reduced aBMD in men, while skeletal effects in women appeared to be influenced by menopausal status. The weak and mostly non-significant correlations between BTMs and aBMD suggest that impaired bone quality, rather than bone mass alone, may be the primary driver of skeletal fragility in T1D. Hormonal status may further modify these effects in women.

Reliable biochemical measurements are essential to patient care and rely on the correct preanalytical handling of blood samples. In Denmark, whole blood samples are transported from general practitioners to local hospital laboratories daily, and whole blood stability for 10 h is required for analytes to be included in this transportation service in the North Jutland Region. Therefore, this study aimed to determine the stability of 17 analytes in whole blood during transportation and storage for 6 and 10 h at room temperature (21 °C). Ten randomly selected participants were included in the Department of Clinical Biochemistry at Aalborg University Hospital. Three serum vacutainer tubes were collected from each participant, and 17 analytes (lipoprotein a, immunoglobulin G1, β-2-Microglobulin, κ free light chain, λ free light chain, peptidyl peptidase A, protein, apolipoprotein B, insulin-like growth factor 1, somatotropin, thyroxin binding globulin, anticardiolipin antibodies IgM, prolactin, thyroid peroxidase antibodies, thyroglobulin, thyroglobulin antibodies,17-Hydroxyprogesterone) were measured at baseline, after 6 h, and after 10 h. All analytes showed 6- and 10-hour stability within the limits of the preestablished analytical variation, reflected by coefficients of variation, in the laboratory (accredited by ISO-15189). Thus, transportation and storage of whole blood at room temperature for 6 and 10 h did not result in significant changes in the levels of the 17 studied analytes. Therefore, all analytes were suitable for the transportation service in the North Jutland Region, Denmark.

Monoclonal gammopathy has been reported to interfere with several laboratory measurement results. We investigated potential interference in monoclonal gammopathy on immunoglobulin A (IgA), immunoglobulin G (IgG), and immunoglobulin M (IgM) concentrations using three different routine chemistry instruments: Alinity (Abbott Laboratories), Cobas 8000 (Roche Diagnostics) and Optilite (Binding Site) at the Department of Clinical Biochemistry, Aalborg University Hospital, Denmark. Blood samples collected from 216 patients with known monoclonal gammopathy were analyzed on Alinity, Cobas and Optilite. Diagnoses were ascertained from clinical records. Scatter plots with Passing-Bablok regression were used to investigate associations between concentrations of IgA, IgG and IgM measured with each of the different instruments. Furthermore, comparison of IgG analyses on Alinity, Optilite and Cobas according to monoclonal IgM concentration was explored with Bland-Altman plots. A total of 81 patients were identified with IgM type monoclonal gammopathy and 8 of these patients (10%) had analytical interference as reflected by more than 25% decrease in the level of IgG measured on Alinity as compared to Optilite and Cobas. All blood samples with interference on IgG measurement using Alinity were from patients with lymphoplasmacytic lymphoma/Waldenstr & ouml;ms macroglobulinemia and all of them had monoclonal IgM concentrations above 10 g/L. This study identified a source of interference from IgM monoclonal gammopathy on IgG measurement performed using Alinity. The interferences caused falsely low results of IgG which is important to recognize to ensure proper patient management.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Objective Thyroid disease in women of reproductive age is mainly of autoimmune origin, and thyroid peroxidase antibodies (TPO-Ab) as well as thyroglobulin antibodies (Tg-Ab) are key markers. Adding to this, much focus in pregnancy is on euthyroid women who are thyroid antibody positive. Evidence to substantiate the cut-offs for the definition of thyroid autoantibody positivity in early pregnant women is warranted. Methods Stored serum samples from 14,030 Danish pregnant women were used for the measurement of TPO-Ab, Tg-Ab, TSH, and free thyroxine (ADVIA Centaur XPT, Siemens Healthineers). Among all women, a reference cohort of 10,905 individuals was identified for the establishment of antibody cut-offs. Percentile cut-offs for TPO-Ab and Tg-Ab were determined using regression on order statistics (the reference cohort). The established cut-offs were then applied (the full cohort), and frequencies of early pregnancy as well as later diagnosis of hypothyroidism were evaluated. Results The highest established cut-offs (95th, 97.5th, and 99th percentiles) were 59, 68, and 81 U/mL for TPO-Ab and 33, 41, and 52 U/mL for Tg-Ab. When the cut-offs were applied in the full cohort, 11.0, 10.2, and 9.7% were TPO-Ab positive, whereas 13.3, 12.3, and 11.2% were Tg-Ab positive. Antibody-positive women (TPO-Ab and/or Tg-Ab) had higher median TSH and were more likely to have hypothyroidism in early pregnancy and to be diagnosed with hypothyroidism during follow-up. Conclusions This large study established and evaluated pregnancy-specific cut-offs for TPO-Ab and Tg-Ab. The findings are important regarding the classification of exposure in pregnancy and assessment of thyroid autoimmunity per se.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Lymphoma patients often receive high glucocorticoid doses as part of standard therapy. Observational studies have shown a substantial risk of glucocorticoid-induced osteoporosis (GIO) with associated fractures. The aim of the SIESTA trial was to determine if oral alendronate (ALN) is a safe and effective prophylaxis against GIO in lymphoma. SIESTA was a single-center, randomized, double-blinded, phase 2 study of lymphoma patients planned for glucocorticoid-containing chemotherapy. After randomization, patients received weekly ALN 70 mg or placebo for a total of 52 weeks. Bone mineral density (BMD) was assessed at baseline, after completion of chemotherapy (end of treatment [EOT]) (4 to 6 months), and at the end of the study (EOS) (12 months). Vertebral fracture and biomarkers were assessed at baseline and EOS. Patients with baseline BMD assessment and at least 1 follow-up BMD assessment were analyzed for efficacy. The primary endpoint was a change in lumbar spine T-score from baseline to EOS. Of the 59 patients enrolled, 23 of 30 in the ALN arm and 24 of 29 in the placebo arm were analyzed for efficacy. The mean change in T-score from baseline to 12 months at the lumbar spine was +0.15 for ALN and -0.12 for placebo (P = .023). The difference in ΔTEOS between the ALN and placebo groups was larger among females (ALN 0.28; placebo -0.28; P = .01). Biomarker analyses confirmed reduced bone resorption in ALN-treated patients. In conclusion, ALN is a safe and effective primary prophylaxis against loss in BMD following glucocorticoid-containing chemotherapy. Despite reduced BMD loss in the ALN arm, the treatment did not influence fracture risk in this small cohort of patients.

Objective:Metabolic syndrome (MetS), type 1 diabetes (T1D), and type 2 diabetes, are associated with an increased risk of fractures; however, the impact of obesity on bone deficits in diabetes is unknown. We aimed to compare markers of bone structure, bone density, and bone turnover in non-diabetic overweight men with MetS and overweight men with T1D or T2D.Methods and Research Design:In this cross-sectional study we included participants from two previously described study cohorts consisting of participants with diabetes and participants with MetS. Participants underwent dual-energy X-ray absorptiometry measuring areal bone mineral density (aBMD) at the hip and lumbar spine, High Resolution peripheral Quantitative (HRpQCT) scan of the tibia and radius and measurement of circulating bone turnover markers. We compared groups with unpaired t test and performed multiple linear regression with adjustment for age, body mass index, and smoking.Results:We included 33 participants with T1D, 25 participants with T2D, and 34 participants with MetS. Bone turnover markers levels were comparable between T1D and MetS. aBMD at the hip was lower in T1D compared to MetS, also after adjustment. P1NP and Osteocalcin levels were lower among individuals with T2D compared to MetS, whereas aBMD were similar between the groups after multiple adjustments. We observed no difference in volumetric BMD at the tibia or radius between MetS and T1D and T2D, respectively. Participants with T2D had a higher trabecular number and lower trabecular separation compared to individuals with MetS at the tibia, which remained signficant after multiple adjustments.Conclusion:In conclusion, we observed no clinically important differences in bone density or structure between men with T2D, T1D, or MetS. However, men with T2D displayed lower bone turnover compared to MetS highlighting that T2D per se and not obesity, is associated with low bone turnover.

Objectives Indirect data mining methods have been proposed for review of published reference intervals (RIs), but methods for identifying patients with a low likelihood of disease are needed. Many indirect methods extract test results on patients with a low frequency blood sampling history to identify putative healthy individuals. Although it is implied there has been no attempt to validate if patients with a low frequency blood sampling history are healthy and if test results from these patients are suitable for RI review. Methods Danish nationwide health registers were linked with a blood sample database, recording a population of 316,337 adults over a ten-year period. Comorbidity indexes were defined from registrations of hospital diagnoses and redeemed prescriptions of drugs. Test results from patients identified as having a low disease burden were used for review of RIs from the Nordic Reference Interval Project (NORIP). Results Blood sampling frequency correlated with comorbidity Indexes and the proportion of patients without disease conditions were enriched among patients with a low number of blood samples. RIs based on test results from patients with only 1-3 blood samples per decade were for many analytes identical compared to NORIP RIs. Some analytes showed expected incongruences and gave conclusive insights into how well RIs from a more than 10 years old multi-center study (NORIP) performed on current pre-analytical and analytical methods. Conclusions Blood sampling frequency enhance the selection of healthy individuals for reviewing reference intervals, providing a simple method solely based on laboratory data without the addition of clinical information.

ObjectiveCirculating osteoglycin may facilitate the crosstalk between bone and pancreas to empower adaptation of bone mass to whole body energy balance. We aimed to examine whether osteoglycin is associated with bone and metabolic parameters and if osteoglycin levels differ between patients with type 1 and 2 diabetes (T1D and T2D).Design and methodsA cross-sectional study of 190 patients with diabetes mellitus and stable hemoglobin A1c (HbA1c) (97 T1D and 93 T2D) was conducted. S-osteoglycin was analyzed by ELISA. Unpaired t-tests were performed to test differences between patients with T1D and T2D and linear regression analyses were performed to investigate associations between osteoglycin, glycemic markers, bone turnover markers and characteristics.ResultsS-osteoglycin did not differ between patients with T1D and T2D (p=0.10). No associations were present between osteoglycin and age, gender, microvascular complications, HbA1c, or plasma glucose in T1D or T2D patients (p>0.05 for all). S-osteoglycin was not associated with levels of bone turnover markers (C-terminal cross-linked telopeptide of type-I collagen (CTX), P-procollagen type 1 amino terminal propeptide (P1NP), P-osteocalcin (OC), P-sclerostin, S-osteoprotegerin (OPG) or S-Receptor Activator of Nuclear factor Kappa beta Ligand (RANKL)) in neither T1D or T2D patients (p>0.05 for all).ConclusionOsteoglycin levels were similar in T1D and T2D patients. Osteoglycin did not correlate with glucose, HbA1c or any other biochemical marker of bone turnover. Thus, we did not find evidence supporting the existence of an osteoglycin-bone-pancreas axis.Clinical Trial RegistrationClinicalTrials.gov, identifier NCT01870557.

INTRODUCTION:Type 2 diabetes (T2D) is related to an increased fracture risk and low bone turnover. However, the mechanisms are not elucidated. In the present study we investigate the association between glycemic variability and bone turnover markers. METHODS:100 participants with T2D and 100 age and gender matched controls were included in this cross-sectional study. All participants with T2D were equipped with a continuous glucose monitoring (CGM) sensor for 3 days (CGMS iPro Continuous Glucose Recorder; Medtronic MiniMed). The dawn glucose levels were defined as a morning period starting 1 h before breakfast ending 1 h post ingestion. On all participants serum (s)-C-terminal cross-linked telopeptide of type-I collagen (CTX), s-procollagen type 1 amino terminal propeptide (P1NP), and s-sclerostin were measured. RESULTS:Participants with T2D displayed significantly lower levels of the bone resorption marker s-CTX and the bone formation marker s-P1NP compared to controls. S-CTX was significantly negatively associated with the mean amplitude of glycemic excursions (MAGE) and the dawn glucose levels whereas s-P1NP only was significantly negatively associated with the dawn glucose levels while it was borderline significantly associated with MAGE (p = 0.05). S-CTX and s-P1NP were significantly lower among the 50% with the highest dawn glucose levels compared to the 50% lowest dawn glucose levels also after adjustment for age, gender, glycated hemoglobin A1c (HbA1c), and body mass index (BMI). CONCLUSION:We observed that the amplitude of glycemic excursions and rise in dawn glucose was negatively associated with bone turnover markers. Future research is needed to determine whether reduction of the amplitude of glycemic excursions increase bone turnover markers.

Abstract Introduction: Many lymphoma patients receive high doses of glucocorticoids as part of standard therapy, and several recent observational studies have highlighted a possible risk of glucocorticoid-induced osteoporosis (GIO) and excess bone fracture risk. As a substantial fraction of lymphoma patients become long-term survivors, studies that focus on mitigating the negative effects of treatment toxicities on survivorship are important. The objective of the SIESTA trial was to determine if primary prophylaxis with oral alendronate (ALN) is safe and effective against (GIO) in lymphoma patients. Methods: SIESTA was a single-center randomized and double-blinded phase 2 study performed at the Department of Hematology, Aalborg University Hospital, Denmark, enrolling lymphoma patients that were planned for glucocorticoid-containing chemotherapy regimens such as (R-)CVP and all variants of (R)-CHOP. Patients were randomized to weekly oral ALN 70mg or placebo with a treatment duration of 52 weeks. Study assessments included bone mineral density (BMD) measurements at baseline, after completion of chemotherapy at 4-6 months (EOT), and after 12 months, as well as vertebral fracture assessment (VFA) at baseline and at 12 months. The primary study endpoint was change in lumbar spine T-score from baseline to 12 months. Key secondary endpoints were change in T-score from baseline to 12 months at total hip and femoral neck levels, vertebral compression fractures and early T-score changes. Biomarker analyses were exploratory. The target recruitment was 60 patients in a three-year period. Results: A total of 59 patients (36 Diffuse large B-cell lymphoma, 15 follicular lymphoma, 8 other) were enrolled with 22 of 30 patients in the ALN arm and 23 of 29 patients in the placebo arm completing the study (efficacy group). Patient characteristics in the two arms were balanced with exception of more advanced stage diseases (Ann Arbor stage III-IV) in the ALN arm (70·0% vs 41·4%), and a lower median baseline T-score at the lumbar spine in the ALN arm (median T-score -0·6 vs 1·0). Patients in the ALN group received a median of 3,291 mg prednisone versus 3,398 mg for the placebo group. Median change in T-score from baseline to 12 months at the lumbar spine level (primary endpoint) was +0·2 for the ALN arm and -0·2 for the placebo arm (P=0·013) (figure 1), with stronger effect for female patients (median change; ALN +0·25; placebo -0·25) (figure 2). ALN had no effect on BMD for total hip (P=0·30) and femoral neck (P=0·58) at 12 months (figure 1). ALN had no significant early effects on BMD for any measured sites (4-6 months). No new fractures were observed. Nine patients experienced AEs related to the upper gastro-intestinal (GI) system (7 grade 1-2, 2 grade 3-4) with 5 AEs being assessed as related to the study treatment (3 in the ALN group and 2 in the placebo group). One patient (placebo group) discontinued study treatment due to upper GI AE (bleeding ulcer). Biomarker analyses (C-terminal telopeptide cross links (CTX) as marker of bone resorption and N-terminal propeptides of collagen type 1 (P1NP) as marker for bone formation) showed reduced bone resorption for ALN treated patients opposed to the placebo treated patients. From baseline to EOT the mean change in CTX was -0.17 in the ALN group and 0.10 in the placebo group respectively (P<0.001). From baseline to 12 months the mean change in CTX was -0.19 in the ALN group and 0.00 in the placebo group respectively (P=0.002). Interpretation: ALN was a safe and effective primary prophylaxis against GIO in lymphoma patients planned for glucocorticoid-containing chemotherapy regimens. The treatment effects were clinically meaningful across all patient subgroups, but the largest effect size was observed in females. Biomarker analyses supported reduced bone resorption for ALN treated patients. Figure 1 Figure 1. Disclosures Vestergaard: Novo Nordisk Foundation: Other: Head of Research at Steno Diabetes Center North Jutland funded by the Novo Nordisk Foundation, Research Funding. El-Galaly: Abbvie: Other: Speakers fee; ROCHE Ltd: Ended employment in the past 24 months.

Objective Lactose intolerance (LI) may be considered in patients with unspecific gastrointestinal symptoms, but there is no clear consensus on when and how to diagnose the disorder. TheLCT-13910 CC genotype is associated with acquired primary lactase deficiency (adult-type hypolactasia; ATH). We aimed to describe the number of tests and test results in the North Denmark Region considering patient age, geographical origin and repeated testing. Methods Retrospective evaluation of the polymerase chain reaction-basedLCT-13910 genotype tests registered in the clinical laboratory information system (LABKA II) with data linkage to Danish nationwide registers. Results Between 18 May 2007 and 31 December 2018, a total of 23,560 individuals were tested. There was a sevenfold increase in the number of tests performed during the study period. About 9.8% of the tests performed in 2018 were repeated testing in the same individuals. Overall, 8.8% of tested individuals were younger than 5 years, 90.7% were of Danish origin and 5.5% originated from outside of Europe. TheLCT-13910 CC genotype was identified in 13.3% of all tested individuals, in 16.0% of children younger than 5 years, in 6.8% of Danish individuals and in 90.9% originating from outside of Europe. Conclusions In the North Denmark Region, a marked increase in the use of genetic testing for hypolactasia was observed and repeated testing was frequent. Furthermore, the use of the test and the test results were dependent on patient age and geographical origin. Results inform the debate on when and how to use genetic testing in the diagnosing of LI.

Background Medical treatment options for primary hyperparathyroidism are scarce. We aimed to assess the efficacy of denosumab and combined with cinacalcet in patients with primary hyperparathyroidism. Methods In this randomised, single-centre, proof-of-concept, double-blind trial, patients aged at least 18 years with primary hyperparathyroidism were recruited from the Department of Endocrinology, Aalborg University Hospital, Aalborg, Denmark. Key eligibility criteria were a T-score between -1.0 and -3.5 at the lumbar spine, femoral neck, or total hip. Patients were assigned (1:1:1) via permuted block randomisation to receive 30 mg cinacalcet per day plus 60 mg denosumab subcutaneously every 6 months (n=14; combination group) for 1 year, denosumab plus placebo (n=16; denosumab group) for 1 year, or placebo plus placebo injection (n=15; placebo group) for 1 year. Primary outcomes were changes in bone mineral density (BMD) measured by dual x-ray absorptiometry at the lumbar spine, total hip, femoral neck, and distal forearm after 1 year. Additionally, effects on bone-metabolic biochemistry were explored. Patients and investigators were masked. All enrolled patients were included in efficacy analyses. The trial was done in an outpatient setting and is registered at ClinicalTrials.gov, NCT03027557, and has been completed. Findings Between March 14, 2017, and March 16, 2018 we recruited 285 participants. 16 patients were randomly allocated to the denosumab group, 15 to the combination group, and 15 to the placebo group. Dropout was limited to one patient in the combination group. Compared with placebo, BMD improved in groups receiving denosumab: lumbar spine (combination group 5.4% [95% CI 2.7-8.1], denosumab group 6.9% [95% CI 4.2-9.6]; p<0.0001), total hip (combination group 5.0% [3.0-6.9], denosumab group 4.1% [2.5-5.8]; p<0.0001), and femoral neck (combination group 4.5% [1.9-7.9]; p=0.0008, denosumab group 3.8% [1.4-6.3]; p=0.0022]). Changes in BMD at the third distal forearm were borderline significant. Six non-fatal serious adverse events occurred (combination group [n=2], denosumab group [n=1], placebo group [n=3]). The overall prevalence of adverse events did not differ between treatment groups, and no fatal adverse events occurred. Interpretation Evidence suggested denosumab was effective in improving BMD and lowering bone turnover in patients with primary hyperparathyroidism irrespective of cinacalcet treatment and might be a valid option for patients in which surgery is undesirable. Copyright (C) 2020 Elsevier Ltd. All rights reserved.

Background: Transference of reference intervals (RIs) from multicentre studies are often verified by use of a small number of samples from reference individuals or by the use of one serum sample (Serum X for NORIP RI). Despite recommended and appropriate methods, both have inconveniencies and drawbacks. Several attempts have been made to develop an indirect method, which uses historical data from the laboratory. These methods are retrospective relying on older test results. A near prospective method would be preferable for the laboratories introducing new methods or changing analytical platforms. Methods: We performed a data mining experiment using results from our laboratory information system covering patients from a large geographic area. Request patterns for patients with assumed healthy characteristics were identified and used to extract laboratory results for calculation of new RI by an indirect method. Calculated RI and confidence intervals (CIs) were compared to transferred NORIP RI verified by NFKK Reference Serum X. Results: We found that our indirect method and NFKK Reference Serum X in general produced similar results when verifying transference of RI. The method produces results for all stratifications. Only single stratifications and one analyte showed unexplained incongruences to the NORIP RI. Conclusions: Our results suggest using request patterns as a surrogate measure for good health status. This allows for a data mining method for validation of RI or validating their transference, which is likely to be applicable in countries with similar healthcare and laboratory information system.

Aim: Osteocalcin and undercarboxylated osteocalcin are suggested to be endocrine messengers from the bones and have been shown to stimulate insulin secretion from pancreatic β-cells. Insulin is hypothesized to increase the osteoblastic production of osteocalcin. The aim of the study was to investigate whether the route of glucose administration influence the circulating levels of osteocalcin and undercarboxylated osteocalcin. Methods: Twelve healthy males were enrolled in an acute cross-over study where they underwent an oral glucose tolerance test (OGTT), an isoglycemic intravenous glucose infusion (IIGI) and a fasting period (control). Blood samples were collected throughout 180 min and analyzed for osteocalcin and undercarboxylated osteocalcin and compared to insulin, glucose, and gastro-intestinal hormone responses. Results: Neither osteocalcin levels nor undercarboxylated osteocalcin levels over time differed between the OGTT, IIGI, and fasting. Baseline insulin levels and glucose levels were not associated with osteocalcin or undercarboxylated osteocalcin levels. Increases in insulin and glucose levels were neither associated with altered osteocalcin nor undercarboxylated osteocalcin levels. Conclusion: The route of glucose administration does not influence the circulating levels of osteocalcin and undercarboxylated osteocalcin despite the differential insulin and incretin responses. In the acute setting this suggests that insulin does not increase osteoblastic production of osteocalcin in healthy human males.