Epidemiology of Hyponatremia

1
Epidemiology of Hyponatremia

• Nicolaos E. Madias, M.D.
• Chairman, Department of Medicine
• Caritas St. Elizabeths Medical Center
• Maurice S. Segal, M.D. Professor of
  Medicine
• Tufts University School of Medicine

2
Hyponatremia

• A decrease in serum sodium concentration to lt 136
  mmol/l

3
Determinants of the Frequency of Hyponatremia in
Clinical Studies

• Serum sodium level
• Frequency of testing
• Health-care setting
• Patient population/clinical setting
• Other qualifiers (e.g., admission vs.
  hospital-acquired)

4
Epidemiology of Hyponatremia (lt130 mmol/l) in a
General Hospital

• Daily incidence and prevalence of 1 and 2.5,
  respectively
• 67 of all hyponatremia was hospital-acquired
• Mean minimal Na was 125 mmol/l and values lt120
  mmol/l were observed in 12 of the hyponatremic
  patients

Anderson et al. Ann Intern Med. 1985102164-168.
5
Epidemiology of Hyponatremia (lt130 mmol/l) in a
General Hospital
N 196
Anderson et al. Ann Intern Med. 1985102164-168.
6
Postoperative Hyponatremia (lt130 mmol/l) in a
General Hospital

• Developed in 4.4 of 1,088 prospectively studied
  patients
• Frequency of hyponatremia varied according to
  type of surgery renal Tx, 92 cardiovascular,
  23 GI-biliary, 19 orthopedic, 3
  miscellaneous, 0.9
• Mean minimal Na ranged from 125 to 128 mmol/l
  in various groups

Chung et al. Arch Intern Med. 1986146333-336.
7
Postoperative Hyponatremia (lt130 mmol/l) in a
General Hospital
N 48
Chung et al. Arch Intern Med. 1986146333-336.
8
Prevalence of Hyponatremia in a General Hospital
Aberdeen Royal Infirmary, n 33,467
Croal et al. Lancet. 19973501402.
9
Frequency of Hyponatremia in a General Hospital
Erasmus Medical Center, Rotterdam, Netherlands.
Data from a three-month prospective study in all
hospitalized patients (n2,907).
Hoorn et al. Nephrol Dial Transplant 20062170-6
10
Prevalence of Hyponatremia at Initial
Presentation to a Health Care Provider
Tan Tock Seng Hospital, Singapore. Data from
303,577 samples on 120,137 patients available for
analysis
Hawkins. Clin Chim Acta 2003337169-172.
11
Total, Admission, and Hospital-Acquired
Hyponatremia in Acute Hospital Care
Hawkins. Clin Chim Acta 2003337169-172.
12
Increasing Age is a Risk Factor for Hyponatremia
(lt 136 mmol/l) in Acute Hospital Care










Analysis adjusted for gender.
Hawkins. Clin Chim Acta 2003337169-172.
13
Increasing Age is a Risk Factor for Hyponatremia
(lt 116 mmol/l) in Acute Hospital Care








Analysis adjusted for gender
Hawkins. Clin Chim Acta 2003337169-172.
14
Male Gender is a Risk Factor for Hyponatremia in
Acute Hospital Care
Analysis adjusted for age
Hawkins. Clin Chim Acta 2003337169-172
15
Frequency of Hyponatremia (?135 mmol/l) in a
Nursing Home Population

• Most recent serum Na during the past 12 months
• VA nursing home residents (60-103 years old CNS
  disorders, 82 CVD, 60 DM, 21) 18 (21/119)
• Geriatric ambulatory patients (62-91 years old)
  8 (5/60)
• Lowest serum Na during the past 12 months
• Nursing home residents 53 (63/119)
• Abnormal water loading in hyponatremic nursing
  home patients 78 (18/23)

Miller et al. J Am Geriatr Soc. 1995431410-1413.
16
Validity of ICD-9 Code (276.1) for Detection of
Hyponatremia
ICD-9 codes reviewed on 2,632 cases of
hyponatremia identified on the basis of
laboratory data over a 22-month period
Movig et al J Clin Epidemiol 20036530-535
17
Admissions to an Acute Care Hospital that Had
Serum Sodium Measured on Day 1
CSEMC Database, Year 2001. (N 11,042
Admissions)
Sosa et al. J Am Soc Nephrol 200516862A.
18
Hyponatremia in an Acute Care Hospital
CSEMC Database, Year 2001. (N 11,042
Admissions)
Sosa et al. J Am Soc Nephrol 200516862A.
19
Occurrence of Hyponatremia in an Acute Care
Hospital According to Clinical Service
CSEMC Database, Year 2001. (N 11,042
Admissions)
Sosa et al. J Am Soc Nephrol 200516862A.
20
Hyponatremia on the Medical Service in an Acute
Care Hospital
CSEMC Database, Year 2001. (N 11,042
Admissions)
Sosa et al. J Am Soc Nephrol 200516862A.
21
Occurrence of Hyponatremia in Patients with Heart
Failure Admitted to an Acute Care Hospital
CSEMC Database, Year 2001. (N 11,042
Admissions)
Sosa et al. J Am Soc Nephrol 200516862A.
22
Hyponatremia ( 134 mmol/l) in Patients Admitted
with Severe Heart Failure

• ESCAPE trial, 400 patients
• Admission hyponatremia, 21
• Hospital-acquired, 16

Gheorgiade et al. 54th Annual Scientific Session,
American College of Cardiology,1075-149. Year?
23
Hyponatremia in Patients with Chronic Liver
Disease Admitted to an Acute Care Hospital
CSEMC Database, Year 2001. (N 366 Admissions)
Sosa et al. J Am Soc Nephrol 200516862A
24
Hyponatremia (lt130 mmol/l) in Patients Admitted
with Complications of Cirrhosis

• Present in 35 of 155 prospectively studied
  patients (all had ascites)1
• Present in 30 of 191 prospectively studied
  patients (97 had ascites).
• By contrast, it was present in 13.5 of 134
  cirrhotic patients followed in the outpatient
  clinic (plt0.001)2

1. Porcel et al. Arch Intern Med.
2002162323-328 2. Borroni et al. Digest Liver
Dis. 200032606-610.
25
Hyponatremia on the Surgical Service in an Acute
Care Hospital
CSEMC Database, Year 2001. (N 366 Admissions)
Sosa et al. J Am Soc Nephrol 200516862A
26
Hyponatremia in Endurance Exercise

• Prospective analysis of 488 runners in the 2002
  Boston Marathon1
• 13 developed hyponatremia ( 135 mmol/l)
• 0.6 developed severe hyponatremia ( 120 mmol/l)
• Prospective analysis of 605 participants in the
  New Zealand Ironman Triathlon2
• 18 developed hyponatremia (lt 135 mmol/l)

1. Almond et al. N Eng J Med 20053521550-1556
2. Speedy et al. Med Sci Sports Exerc 1999
31809-815.
27
Mortality Rates in Normonatremic and Hyponatremic
Patients
(n 1,330)3
(n 397)1
(n 153)1
(n 169)2
1. Flear, 2. Westwater, 3. Samadi (need citations)
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Discharge Hyponatremia is Associated with Adverse
Outcomes in Patients with Decompensated Heart
Failure
ESCAPE Trial (n 318)
P 0.003

Gheorghiade M et al. JACC 200545 (Suppl.
1)145A.
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Hyponatremia is an Independent Risk Factor for
Hospital Death
4,123 patients age 65 years admitted to a
community hospital. Hyponatremia was associated
with a 2.2 higher relative risk of death after
adjustment for gender, age, diagnosis, length of
stay, history of surgery or a procedure, and
number of diagnoses.
Terzian et al J Gen Int Med 1994989-91
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Association of Community-Acquired Hyponatremia
with Hospital Mortality
44,081 consecutive admissions multivariate
analysis adjusted for age, sex, race, admission
service type, and Deyo-Charlson comorbidity score
Wald et al J Am Soc Nephrol 2006 Abstract.
31
Association of Hospital-Aggravated Hyponatremia
(HAH) with Hospital Mortality
44,081 consecutive admissions multivariate
analysis adjusted for age, sex, race, admission
service type, and Deyo-Charlson comorbidity score
Wald et al J Am Soc Nephrol 2006 Abstract.