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DIABETIC CLINICS IN DODDABALLAPUR ROAD BAMNGALORE Low-density lipoproteins Sixty to seventy per cent of total cholesterol is transported as LDL, and total cholesterol measurements usually reflect LDL levels. In both males and females, coronary heart disease risk is proportional to LDL and total cholesterol. As seen above, LDL supplies cholesterol to peripheral tissues. High concentrations of LDL in the serum accelerate atheroma by interacting with damaged endothelium. Oxidation of LDL accelerates this process. A total cholesterol of 5.5 mmol/L, or LDL of 3.5 mmol/L, is usually considered the upper limit of normal but even these levels seem to be responsible for an increased population risk of atheroma. Populations with lower average levels than these have less coronary disease. Lower levels are beneficial for patients with established coronary disease or multiple risk factors. It is not yet clear whether the lowering of total cholesterol to less than 4.0 (LDL 2.0) provides further benefit or whether a target level is indeed the correct approach. Trials of more aggressive cholesterol lowering are underway.14 Although a reduced HDL level (< 1) is associated with increased risk, there is no evidence as yet that raising HDL has beneficial effects. An elevation of triglyceride levels (> 1.7) is also considered a marker of increased risk, but there is no evidence to what level they should be reduced. Exogenous
BEST DIABETOLOGISTS IN HEBBALA BANGALORE Diabetes Type 1 and type 2 diabetes and impaired glucose tolerance (IGT) are associated with an increased risk of coronary disease, peripheral vascular disease and cerebrovascular disease.21 Diabetics have a two- to threefold risk of coronary disease at all ages and those with IGT have a 1.5-fold risk. Diabetes is a stronger risk factor for women (3.3 times) than for men (1.9 times). The excess risk for type 1 patients is largely confined to those with diabetic renal disease. All type 2 patients are at increased risk.22 Diabetes is thought to increase coronary heart disease because: n increased insulin levels result in increased hepatic synthesis of LDL and triglycerides, causing a mixed dyslipidaemia n insulin resistance, which is characteristic of type 2 diabetes, is associated with numerous other cardiovascular risk factors: dyslipidaemia, hypertension, endothelial dysfunction and microalbuminuria n hyperglycaemia itself may cause endothelial damage n glycosylated LDL may be more atherogenic than non-glycosylated LDL. Table 1.12 Glucose tolerance, current WHO definitions (venous plasma glucose) Fasting glucose 2-hour post-glucose load (mmol/L) Normal glucose regulation < 6.0 < 7.8 Impaired fasting glucose 6.1–6.9 < 7.8 Impaired glucose tolerance < 7.0 7.8–11.0 Diabetes > 7.0 > 11.1 16 PRACTICAL CARDIOLOGY Glycaemic control The UKPDS Trial has shown a very significant reduction in the microvascular complications of diabetes with improved glycaemic control but the improvement in macrovascular complications did not quite reach significance. Nevertheless, the UKPDS trialists estimate that each 1% reduction in HbA1c leads to a 14% reduction in cardiovascular risk. Diabetics tend to have more diffuse coronary disease. shows a diffusely diseased right coronary artery from a type 2 diabetic patient before and after coronary stenting . Coronary artery surgery involves a higher risk for diabetics, and graft disease and progression of native disease occur earlier in these patients. Nevertheless, diabetics probably have a better prognosis after surgical revascularisation than after angioplasty because of their higher risk of restenosis following angioplastY
THE BEST DIABETOLOGISTS IN HSR LAY OUT BANGALORE Diabetes Type 1 and type 2 diabetes and impaired glucose tolerance (IGT) are associated with an increased risk of coronary disease, peripheral vascular disease and cerebrovascular disease.21 Diabetics have a two- to threefold risk of coronary disease at all ages and those with IGT have a 1.5-fold risk. Diabetes is a stronger risk factor for women (3.3 times) than for men (1.9 times). The excess risk for type 1 patients is largely confined to those with diabetic renal disease. All type 2 patients are at increased risk.22 Diabetes is thought to increase coronary heart disease because: n increased insulin levels result in increased hepatic synthesis of LDL and triglycerides, causing a mixed dyslipidaemia n insulin resistance, which is characteristic of type 2 diabetes, is associated with numerous other cardiovascular risk factors: dyslipidaemia, hypertension, endothelial dysfunction and microalbuminuria n hyperglycaemia itself may cause endothelial damage n glycosylated LDL may be more atherogenic than non-glycosylated LDL.
THE BEST DIABETOLOGISTS IN HSR LAY OUT BANGALORE Diabetes Type 1 and type 2 diabetes and impaired glucose tolerance (IGT) are associated with an increased risk of coronary disease, peripheral vascular disease and cerebrovascular disease.21 Diabetics have a two- to threefold risk of coronary disease at all ages and those with IGT have a 1.5-fold risk. Diabetes is a stronger risk factor for women (3.3 times) than for men (1.9 times). The excess risk for type 1 patients is largely confined to those with diabetic renal disease. All type 2 patients are at increased risk.22 Diabetes is thought to increase coronary heart disease because: n increased insulin levels result in increased hepatic synthesis of LDL and triglycerides, causing a mixed dyslipidaemia n insulin resistance, which is characteristic of type 2 diabetes, is associated with numerous other cardiovascular risk factors: dyslipidaemia, hypertension, endothelial dysfunction and microalbuminuria n hyperglycaemia itself may cause endothelial damage n glycosylated LDL may be more atherogenic than non-glycosylated LDL.
SAMIKSHA HEART AND DIABETIC CARE IN YELAHANKA NEW TOWN Dyslipidemia Average total serum cholesterol and low-density lipoprotein (LDL) cholesterol levels increase in men until approximately age 70 and then level off. In women, total serum cholesterol and LDL-cholesterol levels rise sharply after menopause and average 15–20 mg/dL higher than in men after age 60. Highdensity lipoprotein (HDL) cholesterol levels average about 10 mg/dL higher in women than in men throughout adult life. Although the strength of association of cholesterol levels with cardiovascular disease declines with age, in part due to the confounding effects of comorbid conditions and nutritional factors, low HDL-cholesterol levels and high total cholesterol to HDL-cholesterol ratios remain independent predictors of coronary events in older persons, including those over 80 years of age. In addition, observational studies and clinical trials indicate that statin therapy is associated with a reduction in cardiovascular events in moderate to high risk patients up to age 85.3 In the PROSPER trial, for example, which randomized 5804 patients 70-82 years of age to pravastatin or placebo, those receiving pravastatin experienced a 15% reduction in the primary outcome of coronary death, nonfatal myocardial infarction, or nonfatal or fatal stroke during a mean follow-up period of 3.2 years. Conversely, limited data are available on statin therapy in lower risk patients and in patients over 85 years of age. Treatment of these subgroups must therefore be individualized based on an overall assessment of potential benefits and risks.
THE BEST CARDIOLOGISTS IN YELAHANKA nvestigations of possible or probable stable angina Electrocardiography A standard 12-lead ECG should be obtained in all patients. This is likely to be normal in almost half of patients with subsequently proven coronary artery disease. Nevertheless, an abnormal trace lends weight to the symptoms and favours further investigation. Chest X-ray Routine radiology is not essential but may reveal important co-morbidities. It should always be performed in those with clinical evidence of hypertension, pericarditis (p. 174), heart failure or valvular disease, if only as a baseline. It is similarly indicated for patients with suspected or known pulmonary or systemic disease such as rheumatoid arthritis, COPD or alcoholism. Routine blood tests All patients with suspected angina should have the following routine investigations at presentation (NHF grade A recommendation): n fasting lipids, including total cholesterol, LDLs, HDLs and triglycerides—risk factors n fasting blood sugar—risk factor n full blood count—anaemia exacerbates angina n serum creatinine—impaired renal function is a risk factor and can be worsened by some cardiac investigations. If indicated clinically, thyroid function
SAMIKSHA HEART AND DIABETIC CARE IN YELAHANKA NEWTOWN ''Restrictive Cardiomyopathy (RCM)'' 'Restrictive cardiomyopathy is characterized by impaired diastolicfilling with normal or mildly abnormal systolic function.Idiopathic restrictive cardiomyopathy is a diagnosis ofexclusion when secondary causes such as amyloidosis, sarcoidosis, and hemochromatosis have been excluded. Familialrestrictive cardiomyopathy is extremely rare in the absenceof the above secondary causes. However, sarcomeric genemutations also have been implicated in RCM including ingenes encoding cardiac troponin T, cardiac troponin I, andα-cardiac actin
''SAMIKSHA HEART AND DIABETIC CARE'' Smoking The Framingham study found an 18% increase in coronary events for males and a 31% increase for females for every 10 cigarettes smoked per day. There is more of an association between smoking and myocardial infarction than between smoking and stable angina. Smoking increases the risk of stroke, coronary heart disease and peripheral vascular disease through a number of mechanisms (Table 1.11). Smoking is a major factor in the increased risk of coronary heart disease for women using oestrogen-containing contraceptive pills Some effects of smoking 1 Increased atherogenesis, probably by toxic injury to endothelial cells 2 Hypoxia, resulting in intimal proliferation 3 Thrombogenesis 4 Reduction in HDL 5 Oxidation of lipids 6 Increase in fibrinogen levels Smoking cessation is associated with a rapid decline in death rates from coronary disease, probably because of smoking’s thrombogenic effects. Smoking seems less important as a risk factor in populations with low LDL levels Smoking cessation Many strategies are available to help patients to give up smoking. These should all begin with an explanation of the reasons smoking cessation is worthwhile. Some explanation of the mechanism of its deleterious effects may be helpful. Patients who have recently presented with possible cardiac symptoms may be amenable to advice of this nature. It is also especially important to give strong advice about smoking to patients with multiple existing coronary risk factors. The rapidity at which benefits begin to occur, and the risks and difficulties involved in further cardiac treatment (e.g. coronary surgery) for smokers, should be emphasised. The postoperative risk is considerably higher for smokers, particularly for serious chest infections. This risk falls quickly (within four weeks) once smoking is stopped. Nicotine replacement patches may be helpful and appear safe even for patients with ischaemic heart disease. The drug bupropion, which is a non-tricyclic antidepressant, is now available for patients who wish to stop smoking. This drug seems safe for patients with cardiac disease, at least for those without unstable symptoms. It does not cause conduction abnormalities or increase the risk of ventricular arrhythmias. Patients should be advised to continue smoking when they first start the drug but plan to stop on a particular day after about a week of treatment. The drug is usually continued for at least seven weeks. The starting dose is 150 mg daily and then 150 mg twice a day. It is important to discuss strategies for smoking cessation with the patient and to try to establish a treatment plan that suits the individual. Passive smoking Evidence of an increased cardiovascular risk from environmental smoke has been available for some years.20 Legislation is gradually reducing the risk for people in occupations associated with smoking (e.g. serving in bars and restaurants) but patients with existing ischaemic heart disease should be advised to avoid exposure.
DIABETOLOGISTS IN HSR LAYOUT BANGALORE Obesity and the metabolic syndrome Obesity (body mass index, or BMI, > 30) is associated with an increased risk of all-cause mortality, largely due to an increase in cardiovascular mortality. Central obesity (waist/hip ratio > 0.9 in men and 0.8 in women) confers most risk, probably because of its association with important risk factors. Risk factors associated with obesity include: 1 increased LDL cholesterol and triglycerides 2 reduced HDL cholesterol 3 hypertension 4 glucose intolerance/insulin resistance. Treatment of obesity The benefits of weight loss should be explained to patients. It is suggested that patients keep a food diary, as this makes them more aware of their food intake, which is always underreported, even by people who are not overweight. Appetite suppressants such as sibutramine, a serotonin and noradrenaline uptake inhibitor, can be useful in selected patients. It is contraindicated for patients with a history of stroke or with uncontrolled hypertension. Patients must have a BMI > 30, or other risk factors and a BMI between 25 and 30. Orlistat, a gastrointestinal lipase inhibitor, causes fat malabsorption and diarrhoea when fat intake exceeds 30% of total dietary intake. There are similar guidelines for its use. Table 1.13 Target heart rates Age Target heart rate (based on 60–70% maximal) 30 110–140 40 105–130 50 100–125 60 95–115 1• CORONARY RISK FACTORS 19 There is evidence that gastric banding or bypass can lead to sustained weight loss in very obese patients. The operation can be performed laparoscopically and at much lower risk than for previous open operations. Successful surgery appears to be associated with a reduction in blood pressure, lipid levels and cardiovascular events. The metabolic syndrome Obesity represents part of the definition of this syndrome. It has recently been redefined by the World Health Organisation (WHO) and the US National Cholesterol Education Program (NCEP) Expert Panel. The diagnosis of the metabolic syndrome does not include any estimation of insulin resistance but requires three or more of the following: 1 central obesity (waist circumference > 102 cm in men, > 88 cm in women) 2 impaired glucose tolerance (fasting
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