Liraglutide pharmacokinetics and dose-exposure response in Asian subjects with Type 2 diabetes from China, India and South Korea

AIMS

To investigate the population pharmacokinetics and exposure-response relationship of liraglutide, a human glucagon-like peptide-1 (GLP-1) analogue, in Asian subjects with Type 2 diabetes mellitus.

METHODS

Data were derived from a published 16-week, randomized, double-blind, double-dummy, active-controlled, parallel-group trial of liraglutide in China, India and South Korea. The analysis utilized 2061 pharmacokinetic (PK) samples from 605 subjects exposed to liraglutide 0.6, 1.2 or 1.8 mg once daily. Demographic factors (body weight, age, gender, country) of importance for liraglutide clearance were evaluated. An exploratory exposure-response analysis was conducted to investigate effects on glycated haemoglobin (HbA1c) and body weight.

RESULTS

Estimated liraglutide exposure (area under the curve; AUC) appeared to increase proportionally with increasing liraglutide dose (0.6-1.8 mg). The covariate analysis confirmed previous findings in a global clinical trial. Body weight was a predictor of liraglutide exposure; compared to a reference subject of 67 kg, exposure was 32% lower for maximum (115 kg) and 54% higher for minimum (37 kg) observed body weights. Gender, age and country had no relevant effect on exposure. Exposure-response analysis supported the use of 1.2mg as maintenance dose with the option of individual dose escalation to 1.8 mg to optimize treatment outcomes.

CONCLUSIONS

Exposure appeared to increase proportionally with increasing liraglutide dose in Asian subjects with Type 2 diabetes mellitus. The only PK relevant predictor of exposure was body weight. The exposure-response relationships for HbA1c and body weight in Asian subjects were similar to observations in global populations.

Surface-based mixed effects multilevel analysis of grouped human electrocorticography

Electrocorticography (ECoG) in humans yields data with unmatched spatio-temporal resolution that provides novel insights into cognitive operations. However, the broader application of ECoG has been confounded by difficulties in accurately depicting individual data and performing statistically valid population-level analyses. To overcome these limitations, we developed methods for accurately registering ECoG data to individual cortical topology. We integrated this technique with surface-based co-registration and a mixed-effects multilevel analysis (MEMA) to control for variable cortical surface anatomy and sparse coverage across patients, as well as intra- and inter-subject variability. We applied this surface-based MEMA (SB-MEMA) technique to a face-recognition task dataset (n=22). Compared against existing techniques, SB-MEMA yielded results much more consistent with individual data and with meta-analyses of face-specific activation studies. We anticipate that SB-MEMA will greatly expand the role of ECoG in studies of human cognition, and will enable the generation of population-level brain activity maps and accurate multimodal comparisons.

The relationship between serum 25-hydroxy vitamin D, parathormone and bone mineral density in Indian population

OBJECTIVES

Vitamin D deficiency (VDD) is a global problem. Not all patients with VDD have clinical manifestations or secondary hyperparathyroidism. We studied the interaction between serum 25-hydroxy vitamin D (25OHD), parathormone (PTH) and bone mineral density (BMD) in Indian adolescents and adults.

DESIGN

Population survey.

PATIENTS

A total of 1829 adolescents and 1346 adults aged 50 years and above were analysed in this study.

MEASUREMENTS

Serum biochemistry, 25OHD, PTH and BMD were estimated. Subjects were grouped according to quartiles of serum PTH. VDD was defined as severe (25OHD ≤ 5 ng/ml), moderate (25OHD ≤ 10 ng/ml) and mild (25OHD ≤ 20 ng/ml) and secondary hyperparathyroidism (SHPT) when serum PTH levels >65 pg/ml.

RESULTS

Only 30-40% of subjects with moderate and severe VDD, respectively, had SHPT. BMD decreased from Quartile 1 to Quartile 4 of PTH at all sites among adolescents and adults, with only a marginal decline in serum 25OHD levels between these quartiles. Further, within each PTH quartile, there was no difference in BMD according to categories of VDD. Analysing BMD in the different PTH quartiles, the PTH cut-offs beyond which BMD showed a significant decline, was 35 pg/ml in adolescents and 53 pg/ml in adults.

CONCLUSIONS

Less than half of the subjects with VDD have SHPT. BMD levels start to decline at PTH values currently considered to be normal. These data suggest the need to redefine SHPT in different age groups keeping in mind the relationship between PTH and BMD. This may also influence the decision to supplement subjects with VDD.

Glutamic acid decarboxylase (anti-GAD) & tissue transglutaminase (anti-TTG) antibodies in patients with thyroid autoimmunity

BACKGROUND & OBJECTIVES

Several autoimmune disorders have been reported to be associated with autoimmune thyroiditis and may coexist with other organ-specific autoantibodies. The aim of the present study was to evaluate the presence of tissue transglutaminase (anti-TTG) and glutamic acid decarboxylase (anti-GAD) antibodies in patients suffering from autoimmune thyroiditis as diagnosed by anti-thyroid peroxidase (anti-TPO) antibodies, which may indicate high risk for developing celiac disease or type 1 diabetes mellitus.

METHODS

Five thousand children and 2800 adults were screening as part of a general health examination done on a voluntary basis in four different parts of Delhi. A total of 577 subjects positive for anti-TPO antibody constituted the cases. Equal number of age and sex matched anti-TPO antibody negative controls were randomly selected from the same cohort to form paired case control study. The cases and controls were further divided into two groups as follows: group-1 (children and adolescent <18 yr), group-2 (adults >18 yr). Serum samples of cases and controls were analysed for thyroid function test (FT3, FT4, and TSH), anti-TTG and anti-GAD antibodies.

RESULTS

A total of 1154 subjects (577 cases and 577 controls) were included in this study. Hypothyroidism was present in 40.2 per cent (232) cases compared to only 4.7 per cent (27) in controls (P<0.001). Anti-TTG and anti-GAD antibodies were present in 6.9 and 12.5 per cent subjects among cases compared to 3.5 per cent (P=0.015) and 4.3 per cent (P=0.001) in controls, respectively. Only anti-GAD antibody were significantly positive in cases among children and adolescents (P =0.0044) and adult (P=0.001) compared to controls. Levels of anti-TTG and anti-GAD antibodies increased with increasing titre of anti-TPO antibody.

INTERPRETATION & CONCLUSIONS

Our findings showed high positivity of anti-GAD and anti-TTG antibodies among subjects with thyroid autoimmunity. It is, therefore, important to have high clinical index of suspicion for celiac disease or type 1 diabetes mellitus in patients with autoimmune thyroiditis.

Growth from birth to adulthood and peak bone mass and density data from the New Delhi Birth Cohort

Growth in early life may predict adult bone health. Our data showed that greater height and body mass index (BMI) gain in utero and infancy are associated with higher peak bone mass, and greater BMI gain in childhood/adolescence with higher peak bone density. These associations are mediated by attained adult height and BMI.

INTRODUCTION

To study the relationship of height and BMI during childhood with adult bone mineral content (BMC), areal density (aBMD) and apparent density (BMAD, estimated volumetric density).

METHODS

Participants comprised 565 men and women aged 33-39 years from the New Delhi Birth Cohort, India, whose weight and height were recorded at birth and annually during infancy (0-2 years), childhood (2-11 years) and adolescence (11 years-adult). Lumbar spine, femoral neck and forearm BMC and aBMD were measured using dual X-ray absorptiometry; lumbar spine and femoral neck BMAD were calculated.

RESULTS

Birth length, and height and height gain during infancy, childhood and adolescence were positively correlated with adult BMC (p≤0.01 all sites except birth length with femoral neck). Correlations increased with height from birth to 6 years, then remained constant for later height measurements. There were no associations with BMAD. BMI at birth, and during childhood and adolescence was also positively correlated with BMC (p < 0.01 all sites). BMI at 11 years, and BMI gain in childhood and adolescence, were correlated with aBMD and BMAD (p < 0.001 for all); these correlations strengthened with increasing age of BMI measurement. The associations with height and BMI in early life became non-significant after adjustment for adult height and BMI.

CONCLUSIONS

Greater skeletal growth and BMI gain in utero and during infancy are associated with higher peak BMC, and greater BMI gain in childhood and adolescence is associated with higher peak aBMD and BMAD. These associations are mediated by the attainment of adult height and BMI, respectively.

Comparison of an automated system with conventional identification and antimicrobial susceptibility testing

The present study was designed to compare a fully automated identification/antibiotic susceptibility testing (AST) system BD Phoenix (BD) for its efficacy in rapid and accurate identification and AST with conventional manual methods and to determine if the errors reported in AST, such as the (very major errors) VME (false susceptibility), (major errors) ME (false resistance), and (minor errors) MiE (intermediate category interpretation) were within the range certified by FDA. Identification and antimicrobial susceptibility test results of eighty-five clinical isolates including both gram-positive and negative were compared on Phoenix considering the results obtained from conventional manual methods of identification and disc diffusion testing of antibiotics as standards for comparison. Phoenix performed favorably well. There was 100% concordance in identification for gram-negative isolates and 94.83% for gram-positive isolates. In seven cases, Phoenix proved better than conventional identification. For antibiotic results, categorical agreement was 98.02% for gram-positive and 95.7% for gram-negative isolates. VME was 0.33%, ME 0.66%, MiE 0.99% for gram-positive isolates and 1.23% VME, 1.23% ME, and 1.85% MiE for gram-negative isolates. Therefore, this automated system can be used as a tool to facilitate early identification and susceptibility pattern of aerobic bacteria in routine microbiology laboratories.

A longitudinal pilot proton MRS investigation of the manic and euthymic states of bipolar disorder

Several lines of evidence implicate dysfunction in brain energy production as a key component of bipolar disorder. In particular, elevated brain lactate levels observed in this condition suggest a shift from aerobic to anaerobic metabolism, possibly as a result of mitochondrial abnormalities. Most prior imaging studies of brain metabolites were performed in either euthymic or depressed bipolar patients or compared different populations in different mood states. We sought to measure brain metabolite concentrations in the same patients in both manic and euthymic states. Given the dramatic changes in clinical state of bipolar disorder patients, we hypothesized that previously observed abnormalities in lactate concentrations in bipolar disorder might show state dependent changes. In this study 15 patients (mean age 36.1 years) diagnosed with bipolar I disorder underwent proton magnetic resonance spectroscopy of the anterior cingulate cortex and parieto-occipital cortex during hospitalization for acute mania (mean Young Mania Rating Scale (YMRS) 22.1). Seven of these subjects returned (mean interval 21.16 months) to have imaging repeated while euthymic (mean YMRS 2.0). A group of age- and gender-matched control participants (N=6) were scanned as well. We report that during mania, bipolar disorder subjects had lactate levels comparable to healthy control subjects but during euthymia these levels were significantly reduced. No significant change was observed for other metabolites. These results implicate mood dependent alterations in energy metabolism in the biology of bipolar disorder. Additionally, this finding has potential use as a biomarker for both evaluating novel treatments as well as diagnostic clarification between mood disorders.