Blood pressure control, microalbuminuria and cardiovascular risk in Type 2 diabetes mellitus

Vitamin D deficiency and metabolic syndrome in elderly Chinese individuals: evidence from CLHLS

Objectives

Both low vitamin D status and metabolic syndrome (MetS) are worldwide concerns, and low 25-hydroxyvitamin D [25(OH)D] levels are associated with MetS; however, related epidemiological evidence based on elderly Chinese individuals, especially those over 80 years of age, is limited. In the present study, we aimed to evaluate the association between serum 25(OH)D and MetS in elderly Chinese individuals.

Method

Serum 25(OH)D was measured in a cross-sectional sample of 2493 elderly people aged 65–112 years from eight areas of China in which the density of centenarians is exceptionally high. MetS was diagnosed according to blood pressure, lipid, and blood sugar levels; waist circumference; and body mass index (BMI). Adjusted multivariable logistic regression was used to analyze the associations between vitamin D and MetS based on different diagnostic criterias.

Results

A total of 890 (35.7%) of the recruited elderly individuals had insufficient levels of vitamin D, and 1029 participants (41.3%) were vitamin D deficient. High serum vitamin D concentrations were associated with a low prevalence of MetS according to the modified Adult Treatment Panel III (ATP III) criteria for adequate versus deficient vitamin D levels (OR: 0.63, 95% CI: 0.45, 0.88) and inadequate versus deficient vitamin D levels (OR: 0.70, 95% CI: 0.52, 0.92). Each 10 ng/ml increase in serum vitamin D was significantly associated with a decreased prevalence of MetS according to the modified ATP III criteria for people with normal waist circumference (WC) (OR: 0.55, 95% CI: 0.43,0.71). However, no significant statistical correlation was found among elderly people with a high WC. Additionally, in the analysis of the individual components, the ORs of adequate versus deficient vitamin D levels were 0.46 (95% CI: 0.30, 0.71) for elevated triglycerides and 0.64 (95% CI: 0.42, 0.97) for reduced high-density lipoprotein cholesterol (HDL-C) after adjustment for other components.

Conclusions

Vitamin D deficiency is very common among elderly Chinese individuals. Vitamin D deficiency may be a risk factor for MetS; however, the association was only statistically significant among elderly people with noncentral obesity. Further studies are needed to examine the causal direction of the association.

Effect of garden cress in reducing blood glucose, improving blood lipids, and reducing oxidative stress in a mouse model of diabetes induced by a high-fat diet and streptozotocin

BACKGROUND

A mouse model in which diabetes mellitus was induced by low-dose streptozotocin (STZ) injection combined with a high-fat diet was used to study the effect of two water cress (Lepidium savitum) preparations. Diabetic mice were treated with dried cress powder or with water-soluble extracts (tested at two doses), together with proper control groups. The mice were evaluated after 4 weeks of continuous intervention for type 2 diabetic and associated markers. We determined blood glucose, body weight, total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), serum insulin levels, and DNA integrity of hepatic cells. The concentrations of malondialdehyde (MDA) and lipid peroxide (LPO) and the activities of four enzymes that are part of the antioxidant defense system were determined in liver samples, as well as gene expression (by semi-quantitative reverse transcription polymerase chain reaction) and enzyme activity of IRS-1, IRS-2, PI3K, AKT-2, and GLUT4.

RESULTS

After 4 weeks of intervention, the levels of TC, TG, and LDL cholesterol were significantly (P < 0.5) decreased and HDL cholesterol was significantly increased. Enzyme activities of liver superoxide dismutase, glutathione, glutathione peroxidase, and catalase were significantly increased, whereas MDA and LPO concentrations were significantly reduced. The transcription level of the five genes assessed was increased, with corresponding increases in protein expression.

CONCLUSION

Oral uptake of garden cress can significantly reduce the blood glucose and improve the blood lipid metabolism of diabetic mice. Considerable improvements in the activity of antioxidant defense enzymes were observed in type 2 diabetic mice that improved the body's antioxidant emergency response. © 2019 Society of Chemical Industry.

Stevioside modulates oxidative damage in the liver and kidney of high fat/low streptozocin diabetic rats

This study investigated the potential of stevioside to prevent oxidative DNA damage in the liver and kidney of type 2 diabetes mellitus (T2DM) using high fat-low streptozocin rat model. Rats were treated daily with 12.5, 25 and 50 mg/kg stevioside orally for 21 days. Levels of biomarkers of T2DM, lipid profile and oxidative stress were assayed spectrophotometrically. The DNA ladder assay method was used to assess DNA fragmentation in the liver and kidney while computational analysis was used to predict the mechanisms of antidiabetic properties of stevioside. Stevioside significantly (p < 0.05) decreased the levels of plasma glucose, insulin, dipeptidyl peptidase IV and activities of kidney angiotensin converting enzyme. Stevioside significantly reduced oxidative stress by decreasing the levels of lipid peroxidation and nitric oxide in the liver and kidney; thereby, reducing the extent of DNA fragmentation in the liver and kidney of the diabetic rats. The in silico analysis showed that the ability of stevioside to exert these effects is linked to its inhibition of beta-adrenergic receptor kinase and G-protein-coupled receptor kinase. The results of this study suggest that the prevention of DNA fragmentation may be an additional benefit of the use of stevioside in the management of T2DM.

[Evaluation of blood pressure control by ambulatory blood pressure monitoring and study of factors associated with poor blood pressure control in 300 treated hypertensive type 2 diabetic patients]

Hypertension is frequently associated with type 2 diabetes and is often difficult to control.

AIM

Evaluate the frequency of controlled hypertension in our type 2 diabetic patients with known and treated hypertension and determine the factors associated with poor blood pressure control.

SUBJECTS AND METHODS

Prospective study concerning 300 type 2 diabetic patients with a known and treated hypertension, sex-ratio: 0.64, mean age: 61.2±9.1 years (37-86). All subjects underwent physical examination, biological investigations and a 24 hours ambulatory blood pressure monitoring (ABPM).

RESULTS

Hypertension was well controlled in 70 patients (23.3%). The concordance rate between clinical measure of blood pressure and ABPM was 70.3%. Subjects with uncontrolled hypertension were older (61.8±8.9 vs 59.1±9.3 years, P<0.05), more frequently of male sex (sex-ratio: 0.77 vs 0.34, P<0.01), smokers (36.4 vs 21.7%, P<0.05) and with abdominal adiposity (P<0.05). Duration of diabetes, body mass index and the frequency of peripheral neuropathy, retinopathy and coronary insufficiency were not different between the two groups. Diabetic nephropathy was more frequent (29.8 vs 16.1%, P<0.05) in the group with uncontrolled hypertension. Loss of circadian blood pressure rhythm was noted in 239 patients (79.6%) and it was more frequently observed in patients with uncontrolled hypertension (84 vs 66%, P<0.001).

CONCLUSION

Our type 2 diabetic patients had a poorly controlled hypertension. Close monitoring of blood pressure with adjustment of antihypertensive treatment are necessary to improve cardiovascular prognosis of our patients.

Association of glycosylated haemoglobin level and diabetes mellitus duration with the severity of coronary artery disease

Diabetes mellitus (DM) is known to cause microvascular and possibly macrovascular complications. This study was performed to find the association between glycosylated haemoglobin (HbA1C) level and the severity of coronary artery disease. One hundred and ten consecutive patients admitted to hospital with acute myocardial infarction were studied. Seventy-eight patients (70.9%) had DM, 73 (93.58%) had HbA1C > 7%, 52 (47.3%) were hypertensive, 19 (17.3%) had a history of smoking and 37 (33.6%) had raised cholesterol. Coronary angiography was carried out in 87 (79.1%) patients and the severity of disease was assessed using the Gensini score. The mean Gensini score was 53.36+/-36.94 and the mean HbA1C was 8.4+/-2.39%. There was a significant association between Gensini score and DM (p=0.003) and between Gensini score and hypertension (p=0.018). HbA1C (r=0.427, p=0.001) and duration of DM (r=0.362, p=0.004) had a positive linear correlation with the Gensini score. Multiple regression analysis showed HbA1C to be an independent factor that influenced the Gensini score (p=0.021).

Albuminuria: a target for treatment of type 2 diabetic nephropathy

Both renal and cardiovascular morbidity and mortality is increased markedly in patients with type 2 diabetes. Besides the classic risk factors and markers such as glucose, blood pressure, blood lipid profile, and lifestyle (smoking, overweight), novel risk markers are identified, among them urine albumin excretion. Levels of urinary albumin excretion greater than normal are observed frequently in patients with type 2 diabetes. Moderately increased levels of albuminuria, so-called microalbuminuria, are predictive both for progressive renal function loss to diabetic nephropathy, and for cardiovascular morbidity and mortality: the higher the albuminuria level, the more chance of renal and cardiovascular complications. More advanced levels of albuminuria (overt albuminuria) are observed in patients in the diabetic nephropathy state. In this condition, renal and cardiovascular risk are extremely high, and again one may observe that the level of albumin excretion is predictive of renal and cardiovascular outcome. Several drug strategies decrease the level of urinary albumin excretion in type 2 diabetic patients. Data on using drugs that intervene in the renin-angiotensin-aldosterone-system (RAAS) are the most extensive and conclusive. RAAS intervention is a very effective strategy to decrease the amount of albumin in the urine, independent from the blood pressure decreasing characteristics of the treatment. RAAS intervention is associated with long-term renal and cardiovascular protection. Importantly, the degree of short-term albuminuria decrease is associated with the degree of renal and cardiovascular protection: the more albuminuria reduction, the more protection. The protective predictive power of the albuminuria effect of RAAS intervention is not related to (or dissociated from) the blood pressure decreasing effect of these drugs. The protective effect of RAAS intervention is present at normoalbuminuric, microalbuminuric, and overt albuminuria levels. This makes albuminuria a target for therapy in type 2 diabetes. New drug strategies that decrease or prevent albuminuria without affecting other risk factors currently are being tested, and not only will add to underscoring the need to treat albuminuria as a separate target, but also will assist in reducing the enormous residual risk burden of individual diabetic patients.

Differential Effects of β-Blockers on Albuminuria in Patients With Type 2 Diabetes

Increases in the cardiovascular risk marker microalbuminuria are attenuated by blood pressure reduction using blockers of the renin-angiotensin system. Such changes in microalbuminuria have not been observed when β-blockers are used. A prespecified secondary end point of the Glycemic Effects in Diabetes Mellitus Carvedilol-Metoprolol Comparison in Hypertensives (GEMINI) trial was to examine the effects of different β-blockers on changes in albuminuria in the presence of renin-angiotensin system blockade. Participants with hypertension and type 2 diabetes were randomized to either metoprolol tartrate (n=737) or carvedilol (n=498) in blinded fashion after a washout period of all antihypertensive agents except for angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. Blinded medication was titrated to achieve target blood pressure, with a-5 month follow-up period. The current analysis examined microalbuminuria, using spot urine albumin:creatinine, in participants who had values at screening and trial end. A greater reduction in microalbuminuria was observed for those randomized to carvedilol (−16.2%Δ; 95% confidence interval, −25.3, −5.9; P =0.003). Of those with normoalbuminuria at baseline, fewer progressed to microalbuminuria on carvedilol versus metoprolol (20 of 302 [6.6%] versus 48 of 431 [11.1%], respectively; P =0.03). Microalbuminuria development was not related to differences in blood pressure or achievement of blood pressure goal (68% carvedilol versus 67%, metoprolol). Presence of metabolic syndrome at baseline was the only independent predictor of worsening albuminuria throughout the study ( P =0.004). β-Blockers have differential effects on microalbuminuria in the presence of renin-angiotensin system blockade. These differences cannot be explained by effects on blood pressure or α1-antagonism but may relate to antioxidant properties of carvedilol.

Hypertension in people with Type 2 diabetes: knowledge-based diabetes-specific guidelines

The International Diabetes Federation (Europe) has updated these guidelines on hypertension management specifically in Type 2 diabetes in the light of recent results of the first prospective, randomized controlled studies to investigate clinical outcomes in people with diabetes and hypertension. The guidelines are knowledge based, i.e. based not only on evidence originating from clinical trials, but also from epidemiological and pathophysiological studies. A successful management strategy requires the following components: 1. Regular surveillance to detect developing hypertension and other cardiovascular (CV) risk factors. 2. Considering more frequent monitoring and review of CV risk factors if any single blood pressure (BP) measurement > 140/85 mmHg (or 130/75 if microalbuminuria); when appropriate, using ambulatory or home monitoring to establish the baseline BP. 3. Considering other CV risk factors, such as a raised albumin excretion rate, in setting the intervention threshold. 4. Individualizing the target BP in accordance with other CV risk factors. 5. Agreeing lifestyle and therapeutic interventions with the patient, with education and empowerment as required. 6. Implementing lifestyle modifications, including controlling calorie, salt and alcohol intake, increased physical activity, weight control and smoking cessation. 7. Therapeutic strategy: the primary goal of therapy is to reduce BP markedly. Combination therapy is often necessary, e.g. an angiotensin converting enzyme (ACE) inhibitor and a diuretic. Some classes are particularly useful for certain patients, notably longer-acting ACE inhibitors, angiotensin 2 receptor antagonists (A2RAs) and calcium antagonists in those at risk of diabetic nephropathy, loop diuretics and thiazides in those at risk of hyperkalaemia, beta-blockers and calcium antagonists (except short-acting dihydropyridines) in patients with angina, beta-blockers and ACE inhibitors after a myocardial infarction or in those with left ventricular dysfunction, and thiazide diuretics and long-acting dihydropyridine calcium antagonists for isolated systolic hypertension. A2RAs should be particularly considered when ACE inhibitors are not tolerated. alpha 1-Blockers should not be considered first line in the absence of outcome data. Cost of drugs will modify these strategies in developing countries. 8. Monitoring response to therapies and, if target levels are not achieved, either intensifying drug therapy if the CV risk justifies it, or reassessing the target. 9. Maintaining a quality assurance strategy. This strategy is summarized in a simple, practical management algorithm.

The role of angiotensin II receptor antagonists in the management of diabetes

Diabetic nephropathy, which develops in about 30% of patients with diabetes, is a progressive condition. It is characterized by increased blood pressure, declining glomerular filtration rate and albuminuria. Lowering of blood pressure in diabetic patients is associated with reduced cardiovascular risk and renal protection. Inhibitors of angiotensin-converting enzyme (ACE) are the current gold standard treatment for hypertension in patients with type I diabetes because, in addition to their blood pressure lowering ability, they are thought to oppose the increased intraglomerular pressure that is mediated in part by angiotensin II. The angiotensin II receptor antagonists, a more recently developed class of antihypertensive agents, appear to be as effective as ACE inhibitors in delaying the progression of renal injury in animal models of diabetes. They act by selectively blocking the binding of angiotensin II to the AT1 receptor and may, therefore, offer a more complete blockade of the renin-angiotensin system than ACE inhibitors. The renal and antihypertensive effects of this class of drug in patients with diabetes are now being investigated in long-term clinical trials. The multicentre Diabetics Exposed to Telmisartan And EnalaprIL (DETAIL) study is a randomized, double-blind, parallel-group comparison of the renal and antihypertensive effects of the angiotensin II receptor antagonist telmisartan and the ACE inhibitor enalapril in 272 patients with type II diabetes. The primary outcome is change in glomerular filtration rate over the 5 years of the study.

Hypertension and diabetes

Hypertension is common in people with diabetes with an estimated prevalence using the new criteria (> or = 140/90) at 70%. The recent large randomized controlled studies in diabetic subjects has clearly shown the benefit of blood pressure lowering with reduction in cardiovascular endpoints and microvascular disease. ACE inhibitors, calcium antagonists, thiazide diuretics and beta-blocking agents have been the agents validated by the trials. The challenge now is to implement antihypertensive therapy to achieve tight blood pressure targets (< or = 140/80), usually requiring dual or even triple therapeutic regimens.