TY - JOUR
T1 - Early diagnosis of thyrotoxic periodic paralysis
T2 - Spot urine calcium to phosphate ratio
AU - Lin, Shih H.
AU - Chu, Pauling
AU - Cheng, Chih J.
AU - Chu, Shi J.
AU - Hung, Yi J.
AU - Lin, Yuh Feng
PY - 2006/12
Y1 - 2006/12
N2 - OBJECTIVES: To identify a clinically reliable index of thyrotoxic periodic paralysis (TPP), a life-threatening emergency with unique and effective therapies. DESIGN: Diagnostic study. SETTING: University teaching hospital. PATIENTS: Fifty-three consecutive patients with hypokalemic paralysis during a 3-yr period and 30 thyrotoxic patients without paralysis as the thyrotoxic control group. INTERVENTIONS: For patients with hypokalemic paralysis, blood and second-void spot urine samples were obtained and measured by routine laboratory prior to therapy. For the thyrotoxic control group, blood and spot urine were collected when they visited outpatient clinics. MEASUREMENTS AND MAIN RESULTS: Twenty-nine patients fulfilled the criteria for TPP. Compared with the thyrotoxic control group, the TPP group had significant decreases in plasma potassium (K) and phosphate concentrations associated with very low urine K and phosphate excretion. Compared with the non-TPP group, the TPP group had significantly lower plasma creatinine and phosphate levels, a significantly higher urine calcium to creatinine ratio (0.25 ± 0.12 vs. 0.08 ± 0.07 mg/mg, p <.001), and a significantly lower urine phosphate to creatinine ratio (0.08 ± 0.05 vs. 0.31 ± 0.23 mg/mg, p <.001). The urine calcium to phosphate ratio had greater discriminatory power between TPP and non-TPP hypokalemic paralysis (4.1 ± 2.3 vs. 0.5 ± 0.6 mg/mg, p <.001). Using a urine calcium to phosphate ratio cutoff value of 1.7 mg/mg, sensitivity and specificity for TPP were 100% and 96%, respectively. CONCLUSIONS: Hypercalciuria and hypophosphaturia are characteristic features of TPP.
AB - OBJECTIVES: To identify a clinically reliable index of thyrotoxic periodic paralysis (TPP), a life-threatening emergency with unique and effective therapies. DESIGN: Diagnostic study. SETTING: University teaching hospital. PATIENTS: Fifty-three consecutive patients with hypokalemic paralysis during a 3-yr period and 30 thyrotoxic patients without paralysis as the thyrotoxic control group. INTERVENTIONS: For patients with hypokalemic paralysis, blood and second-void spot urine samples were obtained and measured by routine laboratory prior to therapy. For the thyrotoxic control group, blood and spot urine were collected when they visited outpatient clinics. MEASUREMENTS AND MAIN RESULTS: Twenty-nine patients fulfilled the criteria for TPP. Compared with the thyrotoxic control group, the TPP group had significant decreases in plasma potassium (K) and phosphate concentrations associated with very low urine K and phosphate excretion. Compared with the non-TPP group, the TPP group had significantly lower plasma creatinine and phosphate levels, a significantly higher urine calcium to creatinine ratio (0.25 ± 0.12 vs. 0.08 ± 0.07 mg/mg, p <.001), and a significantly lower urine phosphate to creatinine ratio (0.08 ± 0.05 vs. 0.31 ± 0.23 mg/mg, p <.001). The urine calcium to phosphate ratio had greater discriminatory power between TPP and non-TPP hypokalemic paralysis (4.1 ± 2.3 vs. 0.5 ± 0.6 mg/mg, p <.001). Using a urine calcium to phosphate ratio cutoff value of 1.7 mg/mg, sensitivity and specificity for TPP were 100% and 96%, respectively. CONCLUSIONS: Hypercalciuria and hypophosphaturia are characteristic features of TPP.
KW - Hyperthyroidism
KW - Hypokalemia
KW - Hypophosphatemia
KW - Paralysis
KW - Urine calcium
KW - Urine phosphate
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U2 - 10.1097/01.CCM.0000242249.10856.49
DO - 10.1097/01.CCM.0000242249.10856.49
M3 - Article
C2 - 16971853
AN - SCOPUS:33751339775
SN - 0090-3493
VL - 34
SP - 2984
EP - 2989
JO - Critical Care Medicine
JF - Critical Care Medicine
IS - 12
ER -