1. Hyponatraemia Research Questions and Directions
Dr Roy L Soiza
NRS Career Research Fellow
Consultant Geriatrician
NHS Grampian

2. Content Why hyponatraemia What is known Questions to be answered
Current and planned research

3. Hyponatraemia: the ignored Geriatric Giant?
Common – 42% of acute geriatric admissions (Hoyle et al JAGS 2007)
Confusion (Miller et al. JAGS 2006)
Falls and impaired mobility (Renneboog et al 2006)
Bone demineralisation (Verbalis et al 2009)
Hip fracture (Gankam Kegne et al 2008)
Increased risk of death, even if mild (Walkar et al 2009)

4. Hyponatraemia and length of stay
Chua et al. Arch Gerontol Geriatr 2007;45:

5. What we know
Hyponatraemia is very common in older people, especially in hospital
It is associated with a range of adverse outcomes including the major geriatric syndromes and death
It usually represents a disorder of water balance but there are numerous potential causes
There are a number of effective treatments
It is frequently ignored or no diagnosis is made in clinical practice

6. Questions What are the common causes of hyponatraemia in old age?
How can we improve diagnosis?
Does treating hyponatraemia improve outcomes?
How should we treat hyponatraemia (if at all)?

7. Adapted from Soiza et al. Rev Clin Gerontol 2008;18:143-158

8. Investigation
Baseline audit (n=40)
Re-audit
(n=31)
Medication review
12 (30%)
18 (58%)
Volaemic assessment
10(25%)
27(87%)
Serum osmolality
13(33%)
16(52%)
Urine osmolality
11(28%)
17(55%)
Urine sodium
Renal/Liver function test
40(100%)
31(100%)
Thyroid function test
35(88%)
30(97%)
Adrenal function test
10(25.7%)
20(65%)

9. Causes of hyponatraemia Baseline Audit Re-Audit
Not documented
24 (60%)
11 (35.5%)
Medications
4 (10%)
7 (22.6%)
SIADH
3 (7.5%)
Dehydration
2 (6.5%)
CCF
1 (2.5%)
Renal/hepatic failure
1(2.5%)
Other causes
1 (3.2%)
Total 40 31

10. Hoyle et al. QJM 2011

11. Correlation between measurements of total body water by deuterium dilutional analysis and bioelectrical impedance analysis in elderly hyopnatraemic patients

12. What treatment for SIADH?
Fluid restriction
Saline infusions
Demeclocycline
Lithium
Diuretics
Salt
Urea
Arginine Vasopressin Receptor Antagonists (vaptans)

13. Future Directions Observational study in trauma orthopaedics:
Prevalence and causes of hyponatraemia in fragility fracture
Evaluate if bioelectrical impedance analysis improves assessment of volaemic status
Conduct a RCT of vaptan therapy for SIADH after fragility fracture
Conduct a RCT of our diagnostic algorithm

14. Declaration of potential conflicts of interest
I am a member of a scientific advisory board for Otsuka (UK)
I am grateful to the organisers and you for your attention

15. References
Chua M, Hoyle GE, Soiza RL. Prognostic implications of hyponatremia in elderly hospitalized patients. Arch Gerontol Geriatr 2007;45:
Gankam Kegne, F., Andres, C., Sattar, L., Melot, C. ,Decaux, G. (2008) Mild hyponatremia and risk of fracture in the ambulatory elderly. QJM 101:
Hoyle GE, Chua M, Soiza RL. Prevalence of hyponatremia in elderly patients. J Am Geriatr Soc 2006; 54(9):1473
Hoyle GE, Chua M, Soiza RL. Volaemic assessment of the elderly hyponatraemic patient: reliability of clinical assessment and validation of bioelectrical impedance analysis. QJM 2011;104:35-39
Miller, M. (2006) Hyponatremia and arginine vasopressin dysregulation: Mechanisms, clinical consequences, and management. JAGS 54:
Soiza RL, Hoyle GE, Chua MPW. Electrolyte and salt imbalance in older people: causes, management and implications. Rev Clin Gerontol 2008;18:
Soiza RL, Talbot HSC. Management of hyponatraemia in older people: old threats and new opportunities. Ther Adv Drug Saf 2011;2:9-17
Verbalis, J.G., Barsony, J., Sugimura, Y., Tian, Y., Adams, D.J., Carter, E.A. et al. (2009) Hyponatremia induced osteoporosis. J Bone Mineral Res 25:
Walkar, S.S., Mount, D.B. and Curhan, G.C. (2009) Mortality after hospitalization with mild, moderate and severe hyponatremia. Am J Med 122: