Oxygen Uptake, Heart Rate and Oxygen Pulse at Maximal Exercise / 대한내과학회지

OBJECTIVES: Despite the fact that determinations of cadiorespiratory fitness levels by exercise stress tests are becoming widely used in healthy individuals as well as in patients with cardiopulmonary diseases, the normal standards in this field have not been well established in Korea. The purpose of this study is to provide normal standards or reference values for the VO2 max, HR max and O2 pulse max for normal Korean adults by age and sex, along with the derivation of regression formulae of these parameters. METHODS: In 1,000 healthy adults (20-66years) consisting of 603men and 397women, symptomlimited maximal exercise was carried out by Bruce protocol, allowing holding on to the hand rail of the treadmill during exercise for the safety purpose. All the subjects were non-athletes and were members of a health center and were more conscious about their health and physical fitness than the ordinary population. RESULTS: The VO2 max and HR max were decreased with age as expected and, as a whole, the values of the VO2 max and HR max of females were approximately 84% and 90% of those of males, respectively. Estimated yearly reductions in the V max for males and females were 0.45 and 0.32mL/kg/min, respectively and those of the HR max were 0.72 and 0.76/min, respectively. The O2 pulse max of the female was approximately 70% of that of the male, and was slightly related to weight and exercise time. The regression equations of the parameters obtained using exercise time (ET, sec), age (A, year), weight (W, kg) and sex (S, O=male; 1= female) were: HR max=215.3-0.74A-5,04S, O2 pulse max= 5.371+0.216W+0.0107ET-1.505S and VO2 max=40.612+1.950ET-0.206A-0.147W-6.060S, CONCLUSION: The VO2 max in our study was higher than hitherto reported. This was primarily due to longer exercise time of the subjects on the treadmill, because they were allowed to hold on to the hand rail during exercise. And also, the fact that our subjects, being members of a health center, might have had higher physical fitness levels than general population could have contributed to the high VO2 max. Thus, we feel that our results could be the ideal target or- reference values to be achieved for those patients or individuals who have to do the tests with holding on to the rail of a treadmill for safety purpose.

Adrenal Myelolipoma Confirmed by Fine Aspiration Biopsy / 대한내분비학회지

Adrenal myelolipomas are rare, benign tumors cornposed of mature fat and bone marrow elements. Most are small, asymptomatic tumors found incidentally at postmortem examination, Fine needle aspiration biopsy can be used to confirm the diagnosis and avoid an unnecessary operation. We report a case of adrenal myelolipoma confirmed by fine needle aspiration biopsy. A 77-year-old woman with complaining of upper abdominal pain for 2 days was found to have an adrenal mass. She took dexamethasone frequently for 3 years due to multiple arthralgia. Ultrasono-graphy showed a 6cm-sized, suprarenal mass and a stone in the gall bladder with thickened wall. Computed tomography and magnetic resonance imaging scan also presented a suprarenal mass. Endocrinologic results were within normal limits. Adrenal myelolipoma was confirmed by computed tomography-guided fine needle aspiration biopsy without surgery.

Acute Renal Failure in Rhabdomyolysis Associated with Furosemide Induced Hypokalemia / 대한신장학회잡지

Though hypokalemia often goes unrecognized as a cause of rhabdomyolysis, its causal relation for acute renal failure can be considered in cases of extreme hypokalemia when combined with rhabdomyolysis. We present the case of a 21-year-old female in whom acute renal failure was developed by myoglobinuria which was associated with furosemide induced hypokalemia. She had taken 2 grams of furosemide daily over 6 months before developing rhabdomyolysis. Initial neurologic examination revealed painful quadriplegia and laboratory findings showed markedly elevated blood CPK, LDH and AST levels with azotemia. Arterial blood gas analysis showed pH 7.439, serum Na 128mEq/L, K 1.5mEq/L, Cl 87mEq/L, HCO3- 12.6mmol/L and calculated anion gap of 29.9 which indicated that she was under the condition of mixed metabolic alkalosis and metabolic acidosis. Though intravenous infusion of potassium chloride improved muscle strength, azotemia and acidemia persisted for several days. This case suggest that large amount of furosemide, when used for a long time, can be result in the acute renal failure by rhabdomyolysis which was caused by hypokalemia.

Cardiopulmonary Response to Maximal Exercise Loading in Professional Soccer Players

BACKGROUND: Although maximal exercise stress tests are widely used in the athletic and medical fields, studies on professional soccer players are few. The purpose of our study is to observe the cardiopulmonary response to maximal exercise loading and the AT in professional soccer players. METHODS: Maximal exercise stress tests were carried out by a ramp protocol using a treadmill on 20 professional soccer players with a mean age of 25.2 years and with over 10 career years. The tests were also done on 21 college students majoring in physical education with a mean age of 19.4 years, which served as the control group. The AT was determined by the V-slope method. RESULTS: In the players, the VO2 max, VCO2 max and O2 pulse max were significantly larger than those in the control group, and the HR max was smaller for their ages. The VE max, VT max and RP max showed not much difference between the 2 groups but the VE max/VO2 max and VE max/VCO2 max were significantly lower in the players. The AT was larger in the players but the AT/VO2 max was essentially similar to that of the control group. CONCLUSION: Our study reveals that the professonal soccer players, despite their mean ages were approximately 6 years older than the subjects in the control group, had larger VO2 max and VCO2 max, and smaller HR max for their ages. The VE max was similar in both groups. This suggests that the players have higher aerobic capacity than the control group and exchange respiratiory gases more efficiently.