what is the association between potassium levels in the body and anorexia nervosa?
TRANSCRIPT
Potassium and AnorexiaChristina Ferraiuolo
HLSC 415
Thesis Question
What is the association between potassium
levels in the body and Anorexia Nervosa?
Ice Breaker
Take two
What kind of micronutrient is potassium?What relationship would it have with the
heart?Do you think there is a connection between anorexia and potassium?
Potassium
Potassium is a micronutrient and an electrolyte
Infant RDI 0.4 g/day Children RDI 3-4 g/day Adult RDI 4.7 g/day Breastfeeding RDI 5.1 g/day
(Zieve,2009)
Potassium Sources
All meats and fish Soy products Fruits: cantaloupe, banana, kiwi,
avocado Vegetables: broccoli, sweet potato, and
tomatoes Milk and yogurt Nuts (Zieve,2010)
Hypokalemia and Hyperkalemia
Too little potassium in the body is called Hypokalemia
Too much potassium in the body is called Hyperkalemia (Zieve,2009)
Anorexia
An eating disorder Body Dimorphic Obsession with weight and food Starvation Exercise excessively Abuse laxatives and diuretics
DSM IV TR Diagnostic Criteria for Anorexia
Intense fear of gaining weight
Distorted self image
Absence of menstrual cycle
Refusal to maintain body weight at healthy range (Dryden-Edwards, 2010)
Anorexia complications
Death Anemia Bone loss Kidney Problems Brain damage Heart failure or abnormal heart rhythm Electrolyte abnormalities (Dryden-Edwards, 2010)
Anorexia and Hypokalemia
Potassium is an electrolyte
Found in food sources
Anorexia patients lose potassium though weight regulation
Fatal electrical alterations of the heart
Thesis Question
What is the association between potassium
levels in the body and Anorexia Nervosa?
Effect of Weight-Regulating Practices on Potassium Level in Patients with
Anorexia or Bulimia Nervosa
Imbierowicz,K., Curkovic, I., Braks, K., Gesier, F., Liedtke, R., & Ernst Jacoby, G. (2004). Effects of weight-regulating practices on
potassium levels in patients with anorexia or bulimia nervosa. European Eating Disorders Review, 12(5), 300-306. doi: 10.1002/erv.591.
Purpose
To define several diagnostic and symptomatic groups and test them separately for their potassium levels
Anorexia with vomiting Anorexia with vomiting and laxative
abuse Anorexia without vomiting
Research Design
Descriptive Epidemiological› Cross sectional survey
Examining causal factors associated with different anorexia and bulimic groups with Hypokalemia
Retrospective study
Methods
397 patients with preexisting eating disorder
Klinik am Korso in Bad Oeynhausen, Germany
Subgroups based on complete symptomatology
Similarities in BMI, age, disease duration
Hypokalemic: < 3.4 mmol/l plasma potassium
Identification of Statistics
Descriptive Inferential Correlation tests
Descriptive Statistics
Standard Deviation Mean Range Median
Inferential Statistics
Mann-Whitney U test Kruskal-Wallis test Analysis of Variance test (ANOVA) Post-hoc test (Scheffe’)
Correlation tests
Pearson’s two-tailed testing Spearman’s correlation testing Multiple linear regression Stepwise Linear Regression (R2)
› Standardized regression coefficient Coefficient of determination
Interpretation of Results
Hypokalemia in purging anorexic (p = 0.001)
Hypokalemia in non-purging anorexic (p=0.82)
Higher frequency (p = 0.001) Severity (p = 0.001) Differences between anorexic
subgroups (p = 0.001)
Results continued
Potassium levels and BMI (r) 0.27 (p=0.001)
Vomiting frequency, laxative abuse and potassium levels (r) -0.38 (p = 0.005)
Mean potassium 2.8 mmol/l
Table 2. Potassium levels and hypokalemia proportion in the subgroups
Weaknesses of the Study
Number of participants Internal Validity
› Recall bias› Selection bias› Confounding variables
Strengths of the Study
Organization External Validity
› Results represent an entire population
Conclusion
Hypokalemia more common in binging and purging anorexics
Potassium losses through stool, urine and vomit
Possibly other factors associated with potassium loss not tested
Thesis Question
What is the association between potassium
levels in the body and Anorexia Nervosa?
Effects of Anorexia Nervosa on Clinical, Hematological, Biochemical, and Bone Density Parameters in Community-Dwelling Adolescent
Girls
Mirsa, M., Aggarwal, A., Miller, K., Almazan, C., Worley, M., Soyka, L., et al. (2004). Effects of anorexia nervosa on clinical, hematological, biochemical, and bone density parameters in community-dwelling adolescent girls.
Pediatrics, 114(6), 1574-1583. doi:10.1542/peds.2004-0540.
Purpose
To determine the medical effects of anorexia on a young population in terms of normal body function
Research Design
Descriptive Epidemiological study› Cross sectional› Prospective
Community dwelling adolescent girls› Anorexia with outpatient care vs. healthy
adolescents 118 adolescent girls
› 60 with DSM IV diagnosed anorexia › 58 healthy- no past history of eating
disorder
Methods Referred by treatment programs in
Boston, MA Prospective data collection at baseline
visit Three month or more community
dwelling Biochemical
› Potassium levels Anthropometric
› BMI
Identification of Statistics
Descriptive statistics Inferential statistics
Descriptive Statistics
Mean Standard Deviation
Inferential Statistics
T-test Univariate regression analysis
› Correlation between variables Stepwise regression analysis
› Significant predictors
Interpretation of Results
Mean serum potassium levels higher in anorexic› AN: 3.8 +/- 0.3 mmol/l › Healthy: 3.6 +/- 0.2 mmol/l
no subject Hypokalemic› Serum potassium< 3.0 mmol/l
Two subjects with history of purging behavior
Weaknesses of the Study
Weakness in planning No hypothesis stated Limited external validity
Strengths of the Study
Comparability to the control and observed group
Diverse referrals decrease selection bias
Limited external validity› Caucasian Adolescent female specific
Conclusion
Normal serum potassium levels Higher in anorexic
› Due to dehydration Total potassium levels may still be low Not at risk even with low BMI Still at risk for cardiac abnormalities No purging behaviors observed
Thesis Question
What is the association between potassium
levels in the body and Anorexia Nervosa?
Overall Conclusion
Potassium levels are influenced by Anorexia
Both suggested potential cardiac risk Differences in studies
› Set potassium level as Hypokalemic› Population studied
Did I answer my question?
Yes!
Both saw changes in extracellular potassium in the Anorexic populations
Future Direction
More research in diverse groups
Identify relationship of purging and potassium levels
Identify other variables not accounted for
Measuring total potassium vs. only plasma
Questions?