A Randomized, Double-Blind, Parallel-Group Phase III Trial Investigating the Glycemic Efficacy and Safety Profile of Fixed-Dose Combination Dapagliflozin and Linagliptin Over Linagliptin Monotherapy in Patients with Inadequately Controlled Type 2 Diabetes with Metformin.

INTRODUCTION: The aim of the study was to evaluate the efficacy and safety of fixed-dose combination (FDC) of dapagliflozin (10 mg) and linagliptin (5 mg) in comparison to linagliptin 5 mg (Trajenta) in patients with insufficiently controlled type 2 diabetes mellitus (T2DM) on metformin monotherapy. METHODS: The double-blind, randomized, multicentric, parallel-group phase III trial screened 287 adult patients with T2DM (age 18-65 years) from 16 sites across India. The recruited subjects were undergoing metformin monotherapy ≥ 1000 mg/day for at least 28 days. Patients with HbA1c of 7.5-10.5% (58-91 mmol/l) (n = 232) after 2 weeks of run-in period with linagliptin monotherapy and placebo dapagliflozin/linagliptin on metformin monotherapy were randomized (1:1) in parallel to once daily dapagliflozin/linagliptin 10/5 mg or linagliptin 5 mg for 16 weeks. Patients were stratified on the basis of HbA1c (≤ 9.0% and > 9.0%; ≤ 75 mmol/l and > 75 mmol/l)). A total of 225 subjects completed 16 weeks of treatment, 115 patients in the test group and 110 patients in the reference group. RESULTS: Dapagliflozin/linagliptin (p = 0.0003) exhibited a greater change in HbA1c from baseline than linagliptin (p < 0.0001) in 16 weeks (mean reduction, - 1.28% vs - 0.83%). Test group showed a significant decrease in fasting plasma glucose (FPG), postprandial plasma glucose (PPG) and body weight compared to the reference group. The FDC was well tolerated with adverse events being more frequent in the reference group. No serious adverse events (SAEs) were reported in the study. CONCLUSION: Dapagliflozin/linagliptin combination is a novel dipeptidyl peptidase 4 (DPP4)/sodium-glucose co-transporter 2 (SGLT2) inhibitor FDC approved in India for patients with T2DM. Potential limitations of this study are a small dose of dapagliflozin (10 mg) in the FDC, a short study duration (30 weeks) and a high minimum threshold for HbA1c (≤ 7.5%; ≤ 53 mmol/l). Results indicate the FDC to be a superior therapeutic option over linagliptin for patients with T2DM on metformin monotherapy. TRIAL REGISTRATION: CTRI/2022/08/044563; 01/08/2022.

Insulin resistance and lipid alterations in subclinical hypothyroidism.

INTRODUCTION: It is known that dyslipidemia and increased insulin resistance were associated with overt hypothyroidism, but their association with subclinical hypothyroidism is conflicting. Aim was to evaluate insulin resistance and lipid alterations in subclinical hypothyroidism. METHODS: Fifty consecutive cases of subclinical hypothyroidism are the subjects of the study. The cases are compared with age, gender and BMI matched controls. Lipid profile, insulin levels, FPG are assessed after overnight fast. Insulin resistance is calculated using HOMA-IR. The correlation between TSH& lipid prolife, TSH & IR was assessed. RESULTS: Total cholesterol (169.37±32.83 vs. 154.5±18.71, p= 0.031) & low density lipoprotein cholesterol (105.76±26.92vs 93.80±16.67, p=0.037) were significantly higher in cases compared to controls. High density lipoprotein cholesterol (44.23±4.65 vs 42.26±3.20, p=0.0507) was lower in cases which showed a trend towards significance. Triglycerides (97.64±39.44 vs. 92.96±43.49,p=0.65) , fasting insulin levels (11.74±7.16 vs 9.77±5.54,p=0.211) and Insulin resistance (2.30±1.49 vs. 1.78±1.09, p=0.11) were elevated but did not differ significantly between the two groups. CONCLUSION: Subclinical hypothyroidism is associated with elevation of TC, LDL-C and non significant increase in TG and insulin resistance. Both lipid profile and insulin resistance did not correlate with severity of hypothyroidism.

Synthesis and conformational studies of peptides from new C-linked carbo-beta-amino acids (beta-Caas) with anomeric methylamino- and difluorophenyl moieties.

New C-linked carbo-beta-amino acids (beta-Caas), Cbz-(S)-beta-Caa-(NHBoc)-OMe (1) and Cbz-(R)-beta-Caa-(NHBoc)-OMe (2), with an additional amine group (methylamino group of NHBoc) at the C-1 position of the lyxofuranoside side chain and Boc-(S)-beta-Caa-(diFP)-OMe (3) and Boc-(R)-beta-Caa-(diFP)-OMe (4), with a C-difluorophenyl (diFP) moiety at the anomeric position of the lyxofuranoside side chain were prepared from D-mannose. Beta-peptides [tetra- and hexapeptides] were synthesized from these beta-Caas, 'epimeric' [at the amine stereocentre (C(beta))], using the concept of 'alternating chirality' to carry out their conformational studies [NMR (CDCl(3)), CD and MD]. In the monomer design, it was envisaged that the presence of an additional amine group in 1 or 2 would help in solubilizing the peptides in water, while, the C-difluorophenyl (diFP) moiety of 3 and 4 is expected to enhance the biological activity. The peptides having 1 and 2, though could not retain their 12-10-mixed helices in water, have shown moderate activity against gram positive and gram negative bacterial strains. The peptides prepared from 3 and 4, much against our expectations, did not display any biological activity.

Positive and negative ion electrospray tandem mass spectrometry (ESI MS/MS) of Boc-protected peptides containing repeats of L-Ala-gamma4Caa/gamma4Caa-L-Ala: differentiation of some positional isomeric peptides.

High-resolution electrospray ionization (ESI) quadrupole time-of-flight and ion trap tandem mass spectrometry has been used to distinguish the positional isomers of a new class of N-blocked hybrid peptides containing repeats of the amino acids, L-Ala-gamma(4)Caa ((l))/gamma(4)Caa((l))-L-Ala [Caa((l)) = Carbo (lyxose) amino acid, derived from D-mannose]. Both MS/MS and MS(3) of protonated isomeric peptides produce characteristic fragmentation involving the peptide backbone, Boc-group, and the side-chain. It is interesting to observe that the abundant y(n)(+) ions are formed when the corresponding amide -NH does not participate in the helical structures in solution phase and relatively low abundance y(n)(+) ions resulted when the amide -NH involves in the H-bonding. Thus, it was possible to identify the amide -NH hydrogens that participate in the helical structures through H-bonding in solution phase. Further, negative ion ESI MS/MS has also been found to be useful for differentiating these isomeric peptide acids.

12/10- and 11/13-mixed helices in alpha/gamma- and beta/gamma-hybrid peptides containing C-linked carbo-gamma-amino acids with alternating alpha- and beta-amino acids.

New classes of alpha/gamma- and beta/gamma-hybrid peptides have been synthesized with novel 12/10- and 11/13-mixed helical patterns, respectively. The alpha/gamma-peptides were derived from the dipeptide repeats with alternating arrays of l-Ala and gamma-Caa((l)) (C-linked carbo-gamma-amino acid from d-mannose), which generated a new 12/10-mixed helix, for the first time, without a beta-amino acid. The beta/gamma-peptides made from an alternating arrangement of beta-Caa((x)) (C-linked carbo-beta-amino acid) and gamma-Caa((x)) (C-linked carbo-gamma-amino acid from d-xylose), on the other hand, resulted in an unprecedented 11/13-helix. The secondary structures in these peptides have been ascertained from detailed NMR studies, and CD spectroscopy and molecular dynamics investigations provided additional support for the structures derived.