1. BNP | Haemochromatosis | Vitamin D Testing in Primary Care

2. 1. BNP 2. Haemochromatosis 3. Vitamin D

3. BNP Key recommendations: BNP is useful as a ‘rule-out’ test of heart failure in acute dyspnoea The use of BNP in primary care is not yet established BNP 1

4. Introduction BNP assays have an important role in the exclusion of heart failure. Normal levels virtually exclude the diagnosis of heart failure High levels effectively confirm the diagnosis Intermediate levels require confirmation by echocardiography BNP 2

5. Underlying pathophysiology BNP: secreted in response to ventricular distension helps regulate salt and water excretion helps maintain blood pressure NT-proBNP and BNP results are not comparable BNP 3

6. Underlying pathophysiology BNP 4

7. BNP is useful as a ‘rule-out’ test of heart failure when a patient presents with acute dyspnoea and the diagnosis is not clear In patients with dyspnoea BNP levels have good sensitivity for heart failure BNP has low specificity – it can be elevated by other conditions such as acute PE or cor pulmonale BNP 5

8. Interpretation of BNP results in acute dyspnoea It is important to interpret the result using the ranges provided by the testing laboratory. Laboratory ranges for low, indeterminate and high results vary between laboratories and the particular assay used. BNP 6

9. The use of BNP in primary care is not yet established BNP and ECG are equally effective for initial workup BNP’s role in identifying patients with asymptomatic ventricular dysfunction not yet determined No clear role for those already on therapy Inconclusive evidence for use in primary care BNP 7

10. Haemochromatosis gene testing Key recommendations: Transferrin saturation and ferritin are used for diagnosis Population screening is not recommended First degree adult relatives of patients should be tested People with haemochromatosis should be monitored with transferrin saturation and ferritin Haemochromatosis 1

11. Defining haemochromatosis Approximately 1 in 7 people are carriers One in 200 are homozygous Occurs in people of Nordic or Celtic ancestry Haemochromatosis 2

12. Haemochromatosis Causes increased iron absorption: ↑ transferrin saturation ↑ iron accumulation ↑ ferritin Iron deposition may cause organ damage Haemochromatosis 3

13. Haemochromatosis Gene C282Y mutation on the HFE gene 90% of people with clinical features are homozygous Other HFE gene mutations have now been recognised Haemochromatosis 4

14. Symptoms of haemochromatosis Fatigue, weakness, arthralgias, impotence, weight loss, abdominal pain and hyperpigmented skin Symptoms are often vague and nonspecific A poor indicator of disease Haemochromatosis 5

15. Serum transferrin saturation and ferritin are the best initial tests ↑ transferrin saturation is usually the first change Ferritin levels rise as iron stores accumulate, but is non-specific 50% transferrin saturation warrants HFE gene testing Haemochromatosis 6

16. Population screening of asymptomatic individuals for haemochromatosis is currently not recommended Haemochromatosis has been suggested for population screening Has not been widely supported Doubts about the cost-effectiveness of a screening programme Haemochromatosis 7

17. Test first degree adult family members Screen using transferrin saturation, ferritin and HFE gene testing Testing in children can be delayed until > 20 years old Partner can be tested to assess their carrier status, which can help determine the child’s risk Counseling should be included in the process Haemochromatosis 8

18. Testing for haemochromatosis When haemochromatosis is suspected, tests should be requested in a cascade manner, with each result suggesting the path of further testing. Haemochromatosis 9

19. Monitoring haemochromatosis Test transferrin saturation and ferritin at least 1-2 yearly Therapeutic phlebotomy is indicated when the ferritin is consistently elevated Target ferritin is < 50 ug/L Gene should only performed one occasion Haemochromatosis 10

20. Vitamin D testing Key recommendations: Increased sun exposure is advisable for people at high risk of vitamin D insufficiency due to inadequate exposure Vitamin D and calcium supplementation is appropriate for people at high risk who cannot increase their sun exposure Vitamin D 1

21. Vitamin D testing Key recommendations – continued: Routine testing of vitamin D levels is not usually necessary prior to or after starting vitamin D supplementation Vitamin D testing is appropriate for people in specific situations Vitamin D 2

22. Introduction Rickets and osteomalacia are rare Increasing concern of vitamin D levels in some people  vitamin D levels more common in older people International interest in vitamin D supplementation for older people Vitamin D 3

23. Pathophysiology There are two main forms of vitamin D: Vitamin D3 (cholecalciferol): produced in the skin by the action of UV light Vitamin D2 (ergocalciferol) produced by plants Most vitamin D is produced as a result of exposure to sunlight Food provides ~ 10% of vitamin D Vitamin D 4

24. Recommended sun exposure Daily exposure ~ 15% of body surface to 1/3 MED will provide sufficient vitamin D Older people and dark skinned people require more exposure Avoid deliberate exposure between 10:00 and 14:00 Glass blocks vitamin D production Vitamin D 5

25. Recommended sun exposure Dec - Jan July - Aug RegionAt 10:00 or 14:00 At 12:00 Minutes Auckland6 – 8 Minutes 30 – 47 Minutes 24 Minutes Christchurch6 – 9 Minutes 49 – 97 Minutes 40 Minutes Vitamin D 6

26. People at risk of low vitamin D levels Older people in residential care Older people admitted to hospital Patients with hip fracture Dark-skinned men and women (particularly if veiled) Mothers of infants with rickets People unable to obtain regular sun exposure Vitamin D 7

27. Supplementing with cholecalciferol Supplementation may be given without testing for asymptomatic people at risk of low vitamin D because it is safe and relatively inexpensive, whereas testing is expensive Vitamin D 8

28. Supplementing with cholecalciferol Supplementation reduces the risks of fractures in the elderly, particularly those in institutions Supplementation must be combined with an adequate calcium intake the evidence is conflicting for other groups at risk of vitamin D deficiency Vitamin D 9

29. Cholecalciferol Dose An appropriate dose is a single tablet of cholecalciferol 1.25 mg (50,000 IU) monthly by mouth This dose is effective and not associated with risk of toxicity For effective supplementation adequate calcium intake is required (1.5 g daily). This may require calcium supplementation Vitamin D 10

30. Consider supplementation rather than testing Vitamin D testing is expensive Likely to be positive in people at high risk. Reasonable to supplement asymptomatic at risk people without testing Vitamin D 11

31. When should I test for vitamin D Unexplained raised serum alkaline phosphatase or low calcium or phosphate Atypical osteoporosis Unexplained proximal limb pain in older people Unexplained bone pain, unusual fractures or other evidence suggesting metabolic bone disease. (Consider specialist advice for people in this category) Vitamin D 12