Hypertension in diabetes: The role of the vasculature

Systolic Blood Pressure to Diastolic Blood Pressure Ratios in Diabetic and Non-diabetic Patients: Deviation from Golden Ratio

INTRODUCTION

Cardiovascular measures like, systolic to diastolic time intervals on ECG recordings, end-diastolic to end-systolic diameters of the left ventricle on echocardiography, pulmonary and systemic hemodynamic measures have gained an interest in terms of Golden ratio or Golden proportions. Ratio of SBP to DBP as a reflection of GR has been recently evaluated in patients who have undergone ABPM to assess the presence of hypertension.

AIM

To assess and compare the ratios of SBP to DBP as a reflection of GR in 24 h ABPM recordings in patients with and without DM who were not on medical treatment.

METHODS

Six hundred and thirty two patients who underwent ABPM were retrospectively screened and enrolled in the study population in between October 2020 and March 2021. After exclusion of 378 who did not meet the inclusion criteria, 254 patients were enrolled in statistical analysis. Systolic blood pressure and diastolic blood pressure measurements were also averaged for the day and the night spans according to the patients' reported time of waking up and going to bed. The ABPM was programmed to measure blood pressure every 45 min during both the day time and night time periods RESULTS: Among those 254 patients included in statistical analysis, 212 patients were classified as non-diabetic and 42 patients as diabetic. SBP/DBP ratios were significantly higher in diabetics compared to those of non-diabetics in all time spans (1.698 vs 1.631, p = 0.041 for 24 h; 1.689 vs 1.618 p = 0.032 for day-time; 1.74 vs 1.66 p = 0.037 for night time). In non-diabetic patients interestingly day time SBP/DBP gave almost the same value of GR i.e 1.618, likewise the 24 h value of SBP/DBP gave the value of 1.631 which was so close to GR. On the other hand SBP/DBP ratios for all time spans were deviated far from the 1.618 in diabetic patients CONCLUSION: We have shown that systolic to diastolic blood pressure ratios of patients with DM are significantly higher than those without DM. These differences are mainly to due to the lower DBP of diabetic patients compared to non-diabetic patients. Beyond these differences SBP/DBP ratio of non-diabetic patients has shown close proximity to 1.618 known as golden ratio.

Multi-ethnic differences in HbA1c, blood pressure, and low-density-lipid cholesterol control among South Africans living with type 2 diabetes, after a 4-year follow-up

Purpose

Our study set out to examine if disparities in control of glycated hemoglobin (HbA_1c), blood pressure (BP), and low-density-lipoprotein cholesterol (LDL-C) existed among an urban multi-ethnic cohort of South Africans, living with type 2 diabetes mellitus (T2DM).

Patients and methods

This longitudinal, retrospective study consisted of 261 men and women with previously diagnosed T2DM who attended Charlotte Maxeke Johannesburg Academic Hospital, South Africa across two time periods 2009 and 2013. Demographic and clinical data were extracted from consecutive medical records. The primary outcome was to determine achievements in HbA_1c, BP, and LDL-C among ethnic groups using evidence-based goals.

Results

The mean age of the cohort was 64 (±10.6) years, females represented 55%, and the self-reported diabetes duration was 16 (±10.6) years as at 2013. Black Africans (42.9%, n=112 of 261) were more likely to reach the HbA_1c target (<7%) and less likely to have had retinopathy, nephropathy, or cardiovascular disease. Over two-thirds of mixed-ancestry patients attained the BP target (<140/80 mmHg), while 90.2% of Caucasians achieved LDL-C goals (<2.5 mmol/L). Overall, across the ethnic groups studied, we found that HbA_1c control deteriorated over time, although BP levels remained the same and LDL-C levels drastically improved.

Conclusion

There was poor control of HbA_1c, BP, and LDL-C across all ethnic groups. Although a minority achieved recommended targets, some ethnic groups appeared to have worse control than others. Timely aggressive actions in particularly high-risk ethnic groups will prevent/delay the complications commonly associated with T2DM.

Diastolic pressure in type 2 diabetes: can target systolic pressure be reached without "diastolic hypotension"?

The practicality of vigorous lowering of systolic pressure in diabetes to <130 mmHg remains uncertain. Baseline blood pressure data from several recent trials indicate that, in diabetic subjects, there is nearly a fourfold excess in systolic pressure (the difference between baseline pressure and target pressure) over diastolic pressure with respect to the recommended systolic/diastolic target pressure of <130/80 mmHg. Additionally, systolic pressure was 2-3 mmHg higher and diastolic pressure was 1-3 mmHg lower in diabetic hypertensive than in nondiabetic hypertensive individuals, which adds approximately 4 mmHg to pulse pressure and also to the difference between the excess systolic and excess diastolic pressure. We attempted to force (titrate both systolic and excess diastolic pressure) systolic and diastolic blood pressure to <130/85 mmHg based on Joint National Committee VI guidelines in the setting of a clinical practice in 257 diabetic patients. Although target systolic pressure was attained in a third of this cohort, in 57% of the patients, the attained diastolic pressure was <or=70 mmHg. Patients with final diastolic pressure <70 mmHg were older, had a higher prevalence of coronary artery disease, and had higher initial systolic and pulse pressures. Review of achieved blood pressure in studies such as the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) indicates that a significant fraction of the diabetic subjects' diastolic pressure was also driven down to <70 mmHg or even <60 mmHg. Thus, attempted lowering of blood pressure to target systolic pressure is associated with inordinate lowering of diastolic pressure in a significant number of patients. Whether the benefits of tight systolic control to <130 mmHg outweigh the risks of excessive diastolic reduction, especially in older diabetic subjects or diabetic patients with coronary artery disease, remains unresolved.

Adiponectin: linking the metabolic syndrome to its cardiovascular consequences

Obesity and its related disorders, glucose intolerance, hypertension and hyperlipidemia, collectively named the metabolic syndrome, result in substantial cardiovascular morbidity and mortality. Recent data point to several underlying regulatory mechanisms through which obesity links these various outcomes. Adipose tissue is now understood to function not merely as a passive energy storage depot but as an active endocrine organ, producing a variety of bioactive substances termed adipocytokines. Adiponectin, an adipocytokine first described as the most abundant protein produced by adipocytes, appears to serve as a central regulatory protein in many of the physiologic pathways controlling lipid and carbohydrate metabolism, and to mediate various vascular processes. Adiponectin displays both anti-inflammatory and antiatherogenic properties. Unlike other adipocytokines, its levels are paradoxically decreased in obesity and insulin-resistance states including metabolic syndrome and diabetes, as well as hypertension and coronary artery disease. This review will detail the relationship of adiponectin to various features of obesity and insulin-resistance syndromes, as well as its relationship to the cardiovascular complications of these disorders.

Managing hypertension in high-risk patients: lessons and promises from the STRATHE and ADVANCE trials

Pharmacological treatment of hypertension represents a cost-effective way of preventing cardiovascular and renal complications. To benefit maximally from antihypertensive treatment, blood pressure should be brought to below 140/90 mmHg in every hypertensive patient, and even lower (< 130/80 mmHg) if diabetes or renal disease co-exists. Such targets cannot usually be reached using monotherapies. This is especially true in patients who present with a high cardiovascular risk. The co-administration of two agents acting by different mechanisms considerably increases the blood pressure control rate. Such combinations are not only efficacious, but are also well tolerated, and some fixed low-dose combinations even have a placebo-like tolerability. This is the case for the preparation containing the angiotensin-converting enzyme inhibitor perindopril (2 mg) and the diuretic indapamide (0.625 mg), a fixed low-dose combination that has been shown in controlled trials to be more effective than monotherapies in reducing albuminuria, regressing cardiac hypertrophy and improving the stiffness of large arteries. Using this combination to initiate antihypertensive therapy has been shown in a double-blind trial (Strategies of Treatment in Hypertension: Evaluation; STRATHE) to normalize blood pressure (< 140/90 mmHg) in significantly more patients (62%) than a sequential monotherapy approach based on atenolol, losartan and amlodipine (49%) and a stepped-care strategy based on valsartan and hydrochlorothiazide (47%), with no difference between the three arm groups in terms of tolerability. An ongoing randomized trial (Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation; ADVANCE) is a study with a 2 x 2 factorial design assessing the effects of the fixed-dose perindopril-indapamide combination and of the intensive gliclazide modified release-based glucose control regimen in type 2 diabetic patients, with or without hypertension. A total of 11 140 patients were randomly selected. Within the first 6 weeks of treatment (run-in phase), the perindopril-indapamide combination lowered blood pressure from 145/81 +/- 22/11 mmHg (mean +/- SD) to 137/78 +/- 20/10 mmHg. Fixed-dose combinations are becoming more and more popular for the management of hypertension, and are even proposed by hypertension guidelines as a first-line option to treat hypertensive patients.