Exchangeable potassium in diabetics

Profound hypokalemia in diabetic ketoacidosis: a therapeutic challenge

OBJECTIVE

To describe profound hypokalemia in a comatose patient with diabetic ketoacidosis.

METHODS

We present a case report, review the mechanisms for the occurrence of hypokalemia in diabetic ketoacidosis, and discuss its management in the setting of hyperglycemia and hyperosmolality.

RESULTS

A 22-year-old woman with a history of type 1 diabetes mellitus was admitted in a comatose state. Laboratory tests revealed a blood glucose level of 747 mg/dL, serum potassium of 1.9 mEq/L, pH of 6.8, and calculated effective serum osmolality of 320 mOsm/kg. She was intubated and resuscitated with intravenously administered fluids. Intravenous administration of vasopressors was necessary for stabilization of the blood pressure. Intravenous infusion of insulin was initiated to control the hyperglycemia, and repletion of total body potassium stores was undertaken. A total of 660 mEq of potassium was administered intravenously during the first 12.5 hours. Despite such aggressive initial repletion of potassium, the patient required 40 to 80 mEq of potassium daily for the next 8 days to increase the serum potassium concentration to normal.

CONCLUSION

Profound hypokalemia, an uncommon initial manifestation in patients with diabetic ketoacidosis, is indicative of severe total body potassium deficiency. Under such circumstances, aggressive potassium repletion in a comatose patient must be undertaken during correction of other metabolic abnormalities, including hyperglycemia and hyperosmolality. Intravenously administered insulin should be withheld until the serum potassium concentration is (3)3.3 mEq/L.

Body composition in adults with Type 1 diabetes at onset and during the first year of insulin therapy

AIMS

To describe body composition in patients with Type 1 diabetes at diagnosis and during the first year after initiation of insulin therapy.

RESEARCH DESIGN AND METHODS

In 10 (eight male and two female) newly onset Type 1 patients, age 31.5 +/- 3.2 years (27-37 years) (sd and range), body mass index (BMI) 20.8 +/- 1.6 (19.2-23.4) kg/m2, body composition was estimated by means of dual-energy X-ray absorptiometry (DXA) whole body scanning supplemented by estimation of total body water (TBW) (isotope dilution technique with 3H2O) at diagnosis and after 1, 3, 6 and 12 months of insulin therapy.

RESULTS

During the first year after onset of diabetes body weight (BW) increased 4.3 +/- 2.9 (0.1-8.3) kg (P = 0.0012) distributed as a 13.3% (1.6 kg) increase in total fat mass (FM) and 4.9% (2.5 kg) increase in lean body soft tissue mass (LBM). The self-reported weight loss at onset was 6.3 +/- 2.5 kg (1.5-10.0 kg). Compared with two reference populations the Metropolitan Life Insurance Co. and a healthy age and sex-matched local DXA scanned group the initial body composition data demonstrated BW 6.2 kg below ideal weight and a significant reduction of the FM (25% or -0.87 sd), whereas LBM was within the expected range.

CONCLUSIONS

During the first year after onset of Type 1 diabetes the mean increase in BW is 6.5% with a 13.3% increase in FM and a 4.9% increase in LBM. Self-reported data on premorbid BW suggest an approximately 10% reduction in BW at onset of Type 1 diabetes. Compared with a healthy reference population initial body composition data demonstrate a 25% reduction of the FM, whereas only a minor and non-significant reduction in the LBM is encountered. These data indicate that uncontrolled diabetes is rather a fat catabolic state than, as previously believed, a protein catabolic state.

Body composition and fat distribution measured by dual-energy x-ray absorptiometry in premenopausal and postmenopausal insulin-dependent and non-insulin-dependent diabetes mellitus patients

The study aim was to measure body composition and fat distribution in premenopausal and postmenopausal women with insulin-dependent ([IDDM] n = 53) and non-insulin-dependent ([NIDDM] n = 32) diabetes mellitus by dual-energy x-ray absorptiometry. IDDM and NIDDM patients had similar, normal lean tissue mass (LTM) and 24-hour urinary excretion of creatinine. Total body and abdominal fat percentages were higher in the NIDDM group (approximately 40%) than in the IDDM group (-27%, P < .001) and were constant with age and menopausal status in both groups. In postmenopausal patients with IDDM, total body and abdominal fat values were less than in postmenopausal healthy women (approximately 27% v approximately 37%, P < .001). In premenopausal patients with NIDDM, total body and abdominal fat were higher than in premenopausal healthy women (approximately 42% v approximately 25%, P < .001). In conclusion, women with IDDM or NIDDM have a normal LTM and probably a normal muscle mass. Total body and abdominal fat were higher for women with NIDDM than for those with IDDM.

Validity of dual X-ray absorptiometry scanning for determination of body composition in IDDM patients

Data on body composition in patients with insulin-dependent diabetes mellitus (IDDM) are scarce. Dual X-ray absorptiometry (DXA) scanning has proved useful for this purpose in other groups of patients. We tested the validity of the DXA scanner for the determination of fat-free mass (FFM) and fat mass in IDDM patients and control subjects, as compared to other reference methods, i.e. total body potassium by 40K whole body counting (TBK), total body water by tritiated water (TBW), bioelectrical impedance analysis (BIA) and 24-h urinary creatinine excretion (Ucrea). A total of 13 healthy controls, 5 males and 8 females, aged 34.2 years +/- SD 10.4, and 11 IDDM patients, 5 males, 6 females, aged 28.1 years +/- 7.3, diabetes duration 4.2 +/- 2.9 (1.0-9.9), were examined. The patients had no long-term diabetic complications and they had normal ophthalmoscopy and urine albumin excretion. The agreement between FFM estimated by DXA and the other methods, expressed as mean difference +/- 2 SD was; for DXA vs. TBK, 0.09 +/- 6.26 and 0.50 +/- 5.26 kg for controls and IDDM patients respectively; DXA vs. TBW, -2.07 +/- 2.56 and -1.07 +/- 4.58 kg; DXA vs. Ucrea, -2.62 +/- 8.02 and 2.00 +/- 10.0 kg; DXA vs. BIA, -7.90 +/- 8.92 and -7.85 +/- 2.32 kg. The results obtained with BIA were significantly different from the other methods for both control subjects and IDDM patients. In conclusion, DXA scanning is a precise and valid method for estimation of fat-free mass in IDDM patients.

Interdialytic weight gain correlates with glycosylated hemoglobin in diabetic hemodialysis patients

Most of the excess mortality and morbidity in diabetic end-stage renal disease patients is ascribed to diabetes-associated cardiovascular disease, which is accelerated by uremia. We compared the interdialytic weight gain in 33 diabetic patients (group 1) undergoing maintenance hemodialysis in an ambulatory facility retrospectively over 3 months, with 25 randomly selected nondiabetic hemodialysis patients (group 2); in addition, we assessed glycemic control in the diabetic subjects using glycosylated hemoglobin (HbA1c). Interdialytic weight gain was expressed as a percentage of the immediately preceding postdialysis weight, and a mean was calculated for each subject. In all subjects, predialysis serum aldosterone, plasma renin activity, and the interdialytic change in serum sodium were measured. Both groups received an equivalent amount of dialysis using a cellulose membrane (mean +/- SD of thrice weekly dialysis: group 1 = 3.8 +/- 0.35 hours, group 2 = 3.86 +/- 0.3 hours; P < 0.5) and had similar predialysis serum creatinine, hematocrit, and serum albumin levels. Group 1 patients had a mean age of 56.5 +/- 11.4 years (age range, 30 to 71 years) and group 2 had a mean age of 55.8 +/- 15.4 years (age range, 29 to 76 years) (P < 0.84). Mean (+/- SD) duration on maintenance hemodialysis was 18.7 +/- 15.3 months (range, 2 to 84 months) for group 1 and 21 +/- 28.9 months (range, 3 to 156 months) for group 2 (P < 0.9). Interdialytic weight gain was 30% greater in group 1 (4.2% +/- 0.19%) than in group 2 (3.2% +/- 0.2%) (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Blunted kaliuresis after an acute oral potassium load in diabetes mellitus

It is unknown whether diabetic patients without renal failure or aldosterone deficiency respond normally to potassium administration. Acute oral potassium-loading was carried out in eight diabetic patients with modestly reduced creatinine clearance (Ccr) and in 11 diabetic patients and 13 controls with normal clearances. Only one diabetic patient manifested an inappropriately low upright plasma aldosterone level (6 ng/dL). The percentage of potassium excreted in 4 hour by both groups of diabetic patients was significantly less than that of the controls (decreased Ccr:21% +/- 6%, normal Ccr:36% +/- 5%, controls:54% +/- 5%; p less than 0.01 and 0.05 respectively). On the other hand, the estimated amount of potassium translocated intracellularly tended to be greater in the diabetic patients (18 +/- 3 mmol; 11 +/- 3 mmol) than controls(7 +/- 2 mmol; p less than 0.005 and 0.1 respectively), and the ratio of the increase in plasma (K) to the amount of potassium retained, was lower in diabetic patients, probably indicating enhanced intracellular potassium translocation. The authors conclude that diabetic patients with normal or only slightly reduced renal function (and no aldosterone deficiency) may have a reduced capacity to excrete an acute potassium load but an enhanced capacity to transfer potassium intracellularly.

Studies on whole-body potassium in non-ketoacidotic diabetics before and after treatment

Serial measurements of whole-body potassium were carried out in 28 diabetic patients, in 23 of whom diabetes had only recently been diagnosed. Eleven patients were treated with insulin, 12 with oral hypoglycaemic agents, and the rest were already on oral hypoglycaemic agents and had developed poor diabetic control; four of these required insulin. Whole-body potassium was measured before treatment was begun (or altered) and again one and six weeks later. Whole-body potassium (ratio of observed to expected) was initially reduced in most of the patients requiring insulin. After control of diabetes whole-body potassium increased significantly in the three groups. The increase in whole-body potassium in the individual patients varied over a wide range, and in patients who were treated with insulin it was often of a similar magnitude to that observed in patients in diabetic ketoacidosis.