Pattern of Disease and Therapy for Diabetes along with Impact of Generic Prescribing on Cost of Treatment among Outpatients at a Tertiary Care Facility

Landscape of pharmacogenetic variants associated with non-insulin antidiabetic drugs in the Indian population

INTRODUCTION

Genetic variants contribute to differential responses to non-insulin antidiabetic drugs (NIADs), and consequently to variable plasma glucose control. Optimal control of plasma glucose is paramount to minimizing type 2 diabetes-related long-term complications. India's distinct genetic architecture and its exploding burden of type 2 diabetes warrants a population-specific survey of NIAD-associated pharmacogenetic (PGx) variants. The recent availability of large-scale whole genomes from the Indian population provides a unique opportunity to generate a population-specific map of NIAD-associated PGx variants.

RESEARCH DESIGN AND METHODS

We mined 1029 Indian whole genomes for PGx variants, drug-drug interaction (DDI) and drug-drug-gene interactions (DDGI) associated with 44 NIADs. Population-wise allele frequencies were estimated and compared using Fisher's exact test.

RESULTS

Overall, we found 76 known and 52 predicted deleterious common PGx variants associated with response to type 2 diabetes therapy among Indians. We report remarkable interethnic differences in the relative cumulative counts of decreased and increased response-associated alleles across NIAD classes. Indians and South Asians showed a significant excess of decreased metformin response-associated alleles compared with other global populations. Network analysis of shared PGx genes predicts high DDI risk during coadministration of NIADs with other metabolic disease drugs. We also predict an increased CYP2C19-mediated DDGI risk for CYP3A4/3A5-metabolized NIADs, saxagliptin, linagliptin and glyburide when coadministered with proton-pump inhibitors (PPIs).

CONCLUSIONS

Indians and South Asians have a distinct PGx profile for antidiabetes drugs, marked by an excess of poor treatment response-associated alleles for various NIAD classes. This suggests the possibility of a population-specific reduced drug response in atleast some NIADs. In addition, our findings provide an actionable resource for accelerating future diabetes PGx studies in Indians and South Asians and reconsidering NIAD dosing guidelines to ensure maximum efficacy and safety in the population.

The LongitudinAl Nationwide stuDy on Management And Real-world outComes of diabetes in India over 3 years (LANDMARC trial)

INTRODUCTION

LANDMARC (CTRI/2017/05/008452), a prospective, observational real-world study, evaluated the occurrence of diabetes complications, glycemic control and treatment patterns in people with type 2 diabetes mellitus (T2DM) from pan-India regions over a period of 3 years.

METHODS

Participants with T2DM (≥25 to ≤60 years old at diagnosis, diabetes duration ≥2 years at the time of enrollment, with/without glycemic control and on ≥2 antidiabetic therapies) were included. The proportion of participants with macrovascular and microvascular complications, glycemic control and time to treatment adaptation over 36 months were assessed.

RESULTS

Of the 6234 participants enrolled, 5273 completed 3 years follow-up. At the end of 3-years, 205 (3.3%) and 1121 (18.0%) participants reported macrovascular and microvascular complications, respectively. Nonfatal myocardial infarction (40.0%) and neuropathy (82.0%) were the most common complications. At baseline and 3-years, 25.1% (1119/4466) and 36.6% (1356/3700) of participants had HbA1c <7%, respectively. At 3-years, population with macrovascular and microvascular complications had higher proportion of participants with uncontrolled glycemia (78.2% [79/101] and 70.3% [463/659], respectively) than those without complications (61.6% [1839/2985]). Over 3-years, majority (67.7%-73.9%) of the participants were taking only OADs (biguanides [92.2%], sulfonylureas [77.2%] and DPP-IV inhibitors [62.4%]). Addition of insulin was preferred in participants who were only on OADs at baseline, and insulin use gradually increased from 25.5% to 36.7% at the end of 3 years.

CONCLUSION

These 3-year trends highlight the burden of uncontrolled glycemia and cumulative diabetes-related complications, emphasizing the importance of optimizing diabetes management in India.