The Role of Genetic Polymorphism in the Formation of Arterial Hypertension, Type 2 Diabetes and their Comorbidity

BACKGROUND

Hereditary component plays a significant role in the formation of insulin resistance (IR) - one of the pathogenetic links of arterial hypertension (AH) and type 2 diabetes mellitus (DM2). However, the genetic predisposition to IR can not be realized and does not manifest itself clinically in the absence of appropriate factors of the environment (excessive nutrition, low physical activity, etc.).

OBJECTIVE

The review summarizes the results of studies which describe the contribution of genetic polymorphism to the formation and progression of AH, DM2 and their comorbidity in various populations.

RESULTS

In many studies, it has been established that genetic polymorphism of candidate genes is influenced by the formation, course and complication of AH and DM2. According to research data, the modulating effect of polymorphism of some genetic markers of AH and DM2 on metabolism and hemodynamics has been established. The results of numerous studies have shown a higher frequency of occurrence of AH and DM2, as well as their more severe course with adverse genetic polymorphisms. At the same time, the role of genetic polymorphism in the formation of AH and DM2 differs in different populations.

CONCLUSION

Contradictory data on the influence of gene polymorphisms on the formation of AH and DM2 in different populations, as well as a small number of studies on the combined effects of several polymorphisms on the formation of comorbidity, determine the continuation of research in this direction.

Canagliflozin as an Initial Therapy in Drug-Naïve Subjects with Type 2 Diabetes Mellitus: A Potential Involvement of Atherogenic Lipids in its Glycemic Efficacy

Background and Objectives

The aim of this study is to investigate canagliflozin as an initial therapy in type 2 diabetes mellitus and to explore the effects on metabolic parameters in relation to effects on glycemic control.

Subjects and Methods

Treatment-naïve subjects with type 2 diabetes mellitus received canagliflozin 50–100 mg/day monotherapy. At 3 months, levels of glycemic and non-glycemic parameters were compared with those at baseline (n = 39). As a comparator, our previous data of baseline glycosylated hemoglobin (HbA_1c)-matched treatment-naïve subjects with ipragliflozin 25–50 mg monotherapy (n = 27) were employed.

Results

Significant reductions in HbA_1c (from 9.96 to 8.33%), fasting blood glucose (−23.9%), homeostasis model assessment-R (HOMA-R, −33.5%), body mass index (−1.8%), and uric acid (UA, −5.2%) levels and significant increases in homeostasis model assessment-B (HOMA-B, 30.1%) levels were observed. Approximately one third of the subjects experienced certain adverse events. Similar results were obtained with ipragliflozin. Baseline levels of HbA_1c, triglycerides, non-high-density lipoprotein-cholesterol (HDL-C), and low-density lipoprotein-cholesterol (LDL-C) were chosen as significant contributing factors for the changes in HbA_1c levels with canagliflzoin, while only baseline HbA_1c levels were selected as such a factor with ipragliflozin. Significant positive correlations between the changes in HbA_1c and changes in non-HDL-C (R = 0.3954) or between changes in HbA_1c and changes in LDL-C (R = 0.4317) were observed with canagliflozin. With ipragliflozin, no such correlations were noted. No correlations between the changes in HbA_1c and changes in body mass index were seen with both drugs.

Conclusions

These results suggest that (1) canagliflozin appears to offer clinically beneficial outcomes as an initial therapy in subjects with type 2 diabetes mellitus, although with certain adverse events. (2) Atherogenic cholesterols including non-HDL-C and LDL-C could be involved in the glycemic efficacy of canagliflozin. This was not the case with ipragliflozin. (3) Unexpectedly, weight reductions with canagliflozin are not associated with its glycemic efficacy.

Understanding and overcoming metformin gastrointestinal intolerance

Metformin is the most widely prescribed drug for patients with type 2 diabetes mellitus and the first-line pharmacological option as supported by multiple international guidelines, yet a rather large proportion of patients cannot tolerate metformin in adequate amounts because of its associated gastrointestinal (GI) adverse events (AEs). GI AEs typically encountered with metformin therapy include diarrhoea, nausea, flatulence, indigestion, vomiting and abdominal discomfort, with diarrhoea and nausea being the most common. Although starting at a low dose and titrating slowly may help prevent some GI AEs associated with metformin, some patients are unable to tolerate metformin at all and it may also be difficult to convince patients to start metformin again after a bout of GI AEs. Despite this clinical importance, the underlying mechanisms of the GI intolerance associated with metformin are poorly known. In the present review, we discuss: the epidemiology of metformin-associated GI intolerance and its underlying mechanisms; genotype variability and associated factors affecting metformin GI intolerance, such as comorbidities, co-medications and bariatric surgery; clinical consequences and therapeutic strategies to overcome metformin GI intolerance. These strategies include appropriate titration of immediate-release metformin, use of extended-release metformin, the promise of delayed-release metformin and gut microbiome modulators, as well as alternative pharmacological therapies when metformin cannot be tolerated at all. Given the available data, all efforts should be made to maintain metformin before considering a shift to another drug therapy.