Endocrinology and the heart

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Endocrinology and the heart

• Dr Rowan Hillson

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Diabetes

• Accelerated atherosclerosis
• Mean life expectancy 45yr-old diab man 20 yrs
• 2-4 x increase in cardiovascular mortality
• 50-60 diabetics die from cardiovascular disease

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Dont miss the boat

• 30 50 of Type 2 diabetic patients have tissue
  damage at diagnosis
• The onset of tissue damage is years before
• Myocardial infarct 20 yrs pre-diagnosis
• Stroke 12 yrs
• Nephropathy 18 yrs
• Amputation 7 yrs
• Retinopathy 7 yrs
• Source Diabetes UK audit/regression
  calculations

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Risk factors in diabetes - glucose

• Glucose trend but not proven (DCCT 41
  reduction in cardiovascular and PVD risks in
  intensive arm NS UKPDS 16 risk reduction MI
  with intensive glucose control p0.052)
• Higher HbA1c linked with higher CHD mortality
• Advanced glycosylation end-products (AGE)
  implicated in atherogenesis
• Glycosylation LDL (more oxidation) HDL
  (impaired cholesterol transport)

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Risk factors in diabetes - BP

• 2 x increase in hypertension in DM
• T2 DM age 45 40, age 75 60 hypertensive
• Hypertension shortens a diabetics life by 6 yrs
• UKPDS 24 risk reduction all endpoints with
  intensive BP control (trend to reduction of MI)

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Risk factors in diabetes - lipids

• Raised Triglyceride (low HDL in T2 DM)
• High cholesterol shortens a diabetics life by 3
  yrs
• Risk rises steeply with each one mmol increase
• HPS 24 reduction major vascular event on
  statin (mean starting cholesterol 5.7)

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Other risk factors in diabetes

• Smoking shortens a diabetics life by 6 yrs
• Microalbuminuria marker for CV risk (diabetic and
  non-diabetic)
• Raised insulin increases CV risk
• Procoagulant state

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MI in diabetes

• Premenopausal women at equal risk to men
• Late, silent /atypical presentation breathless,
  sweating, syncope, unusual chest pain
• Higher mortality from acute myocardial infarct
• Increased risk re-infarction
• MI may complicate other issues e.g. HONK,
  stroke, surgery, foot infection
• DIGAMI insulin for tight control glucose in AMI
  30 reduction in mortality

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Cardiac failure in diabetes

• 2-5 x commoner in diabetes
• Diabetic cardiomyopathy microvascular disease.
  Interstitial and perivascular fibrosis.
• Failure diastolic relaxation LV, reduced ejection
  fraction on exercise
• Hypertension LV hypertrophy
• Coronary artery atheroma diffuse
• Myocardial infarction
• Arrhythmias

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AIMS of diabetic risk factor care

• No smoking
• BMI 18.5-25. Waist circumference lt80cm F, lt94 M
• Exercise regularly
• HbA1c 4.5 6.5 without hypoglycaemia
• BP lt130/80 without postural hypotension
• Cholesterol lt4
• Triglyceride lt 1.3
• (Exercise and weight normalization in IGT reduces
  risk of diabetes)

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Thyrotoxicosis

• Cardiac output up 200-300 , peripheral vascular
  resistance down 50-75, increased contractility,
  cardiac mass, and blood volume.
• Day and night tachycardia
• Palpitations, AF (10-15), SVT, exercise
  intolerance, dyspnoea, wide pulse pressure,
  systolic flow murmur, angina, oedema
• High-output and/or rate-related cardiac failure
• Cardiac failure elderly, AF
• NB drugs clear fast, may need bigger, repeated
  doses

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Thyrotoxicosis

• Carbimazole or propylthiouracil
• B blocker slows tachycardia, improves symptoms
  and usually reverses LV dysfunction
• 6-24 mth course thionamides. Most recur
• Multinodular goitre severe/male/young Graves
  need definitive Rx
• I 131
• Surgery

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Hypothyroidism

• Cardiac output down 50 peripheral vascular
  resistance up 50-60 decreased contractility,
  cardiac mass, blood volume.
• Narrow pulse pressure. 20-40 high dBP
• Bradycardia. Pericardial effusion 30-50
• Cardiac myxoedema
• Dyspnoea, exercise intolerance, angina, oedema
• Raised cholesterol, overweight
• Rx L-thyroxine care in IHD

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Amiodarone

• Normally iodine 0.2 mg/day
• Amiodarone 200-600mg / day
• Lasts for up to 8 mths after stopping
• First 1-3 mths increases FT4 and TSH
• Later TSH may normalize
• Test TFTs preRx and every 3 mths while on
  amiodarone and for a year after stopping
• Harjai et al Ann Int Med 199712663-73

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Amiodarone continued

• Thyrotoxicosis (low TSH, high FT4) 1 23
• More likely in low iodine areas
• Stop amiodarone if possible. B block if possible
• Thionamides may not work, nor may I 131
• Consider surgery if safe
• Hypothyroidism (high TSH, low FT4) 1- 32
• More likely in high iodine area or high thyroid
  antibodies preRx
• Rx L-thyroxine, do not over treat

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Steroid excess

• On steroids, or adrenal/pituitary excess
• Screen with urinary free cortisol
• Overweight
• Diabetes
• Hypertension
• Oedema
• Cardiac disease

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Steroid lack

• Addisons or pituitary cause
• Commonest cause sudden cessation of prolonged
  steroid treatment
• Hypotension and collapse. Cardiac arrest
• Rx IV hydrocortisone
• In Addisons Rx hydrocortisone and
  fludrocortisone. Too much fludro can cause CCF

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Acromegaly

• Hypertension
• Ischaemic heart disease
• Ventricular hypertrophy
• Cardiomyopathy
• Diabetes
• Mortality x 2. Cardiac/stroke

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Polycystic ovary syndrome

• Obese, menstrual disturbance, infertility,
  hyperandrogenism
• Diabetes. Insulin resistant.
• Dyslipidaemia
• Hypertension
• Cardiovascular disease
• Endometrial Ca

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Cardiovascular hormones

• Atrial natriuretic peptide raised in cardiac
  failure in proportion to severity of dysfunction,
  prognostic indicator e.g. after MI
• Endothelin ET1 correlates with severity of LV
  dysfunction, predict mortality
• Adrenomedullin vasodilator therapeutic
  possibilities