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

Review of Evidence for Adult Diabetic Ketoacidosis Management Protocols

BACKGROUND

Diabetic ketoacidosis (DKA) is an endocrine emergency with associated risk of morbidity and mortality. Despite this, DKA management lacks strong evidence due to the absence of large randomised controlled trials (RCTs).

OBJECTIVE

To review existing studies investigating inpatient DKA management in adults, focusing on intravenous (IV) fluids; insulin administration; potassium, bicarbonate, and phosphate replacement; and DKA management protocols and impact of DKA resolution rates on outcomes.

METHODS

Ovid Medline searches were conducted with limits "all adult" and published between "1973 to current" applied. National consensus statements were also reviewed. Eligibility was determined by two reviewers' assessment of title, abstract, and availability.

RESULTS

A total of 85 eligible articles published between 1973 and 2016 were reviewed. The salient findings were (i) Crystalloids are favoured over colloids though evidence is lacking. The preferred crystalloid and hydration rates remain contentious. (ii) IV infusion of regular human insulin is preferred over the subcutaneous route or rapid acting insulin analogues. Administering an initial IV insulin bolus before low-dose insulin infusions obviates the need for supplemental insulin. Consensus-statements recommend fixed weight-based over "sliding scale" insulin infusions although evidence is weak. (iii) Potassium replacement is imperative although no trials compare replacement rates. (iv) Bicarbonate replacement offers no benefit in DKA with pH > 6.9. In severe metabolic acidosis with pH < 6.9, there is lack of both data and consensus regarding bicarbonate administration. (v) There is no evidence that phosphate replacement offers outcome benefits. Guidelines consider replacement appropriate in patients with cardiac dysfunction, anaemia, respiratory depression, or phosphate levels <0.32 mmol/L. (vi) Upon resolution of DKA, subcutaneous insulin is recommended with IV insulin infusions ceased with an overlap of 1-2 h. (vii) DKA resolution rates are often used as end points in studies, despite a lack of evidence that rapid resolution improves outcome. (viii) Implementation of DKA protocols lacks strong evidence for adherence but may lead to improved clinical outcomes.

CONCLUSION

There are major deficiencies in evidence for optimal management of DKA. Current practice is guided by weak evidence and consensus opinion. All aspects of DKA management require RCTs to affirm or redirect management and formulate consensus evidence-based practice to improve patient outcomes.

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.

Assessing body composition of adults with diabetes

Overweight and obesity are associated with the development of type 2 diabetes. Thus, it is important for clinicians to accurately measure and monitor the body composition of at-risk individuals and patients with diabetes. This article reviews valid and reliable field methods and prediction equations for assessing the body composition of obese individuals, as well as persons with type 2 diabetes. We also reviewed research that assessed the validity of practical methods in estimating the body composition of individuals with either type 1 or type 2 diabetes.

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.

Creatinine height index and lean body mass in adult patients with insulin-dependent diabetes mellitus followed for 7 years from onset

The 24-hour urinary creatinine excretion value can be used as an index of protein nutrition; the creatinine height index and lean body mass can be estimated from this value. On the basis of longitudinally measured 24-hour urinary creatinine excretions during the initial 7 years of type 1 diabetes in an incidence cohort of 147 adult patients, we studied creatinine height index and lean body mass and possible relationships to sequential measurements of glycated hemoglobin (HbA1c). The patients were divided into four groups according to their glycemic control during these 7 years: I, HbA1c < 7.4% (n = 37); II, HbA1c 7.4% to 8.2% (n = 37); III, HbA1c 8.3% to 8.9% (n = 38); IV, HbA1c > 8.9% (n = 35). One year after the onset of diabetes, height indices were as follows (% of normal values, median and quartiles): I, 104% (90 to 116); II, 101% (78 to 105); III, 121% (92 to 128); IV, 87% (78 to 109) ([IV] < [I to III]; p < .05). During the following 6 years no significant differences in height index were observed among the four groups of patients at any point in time. Slightly higher calculated lean body mass values were found in the most well-controlled patients, but otherwise no differences were found in lean body mass. It is concluded that, apart from the first year, indices of protein nutrition remain normal during the initial 7 years of type 1 diabetes, even in patients with poor glycemic control.

Non-insulin-dependent (type II) diabetes mellitus

Non-insulin-dependent (type II) diabetes mellitus is an inherited metabolic disorder characterized by hyperglycemia with resistance to ketosis. The onset is usually after age 40 years. Patients are variably symptomatic and frequently obese, hyperlipidemic and hypertensive. Clinical, pathological and biochemical evidence suggests that the disease is caused by a combined defect of insulin secretion and insulin resistance. Goals in the treatment of hyperglycemia, dyslipidemia and hypertension should be appropriate to the patient's age, the status of diabetic complications and the safety of the regimen. Nonpharmacologic management includes meal planning to achieve a suitable weight, such that carbohydrates supply 50% to 60% of the daily energy intake, with limitation of saturated fats, cholesterol and salt when indicated, and physical activity appropriate to the patient's age and cardiovascular status. Follow-up should include regular visits with the physician, access to diabetes education, self-monitoring of the blood or urine glucose level and laboratory-based measurement of the plasma levels of glucose and glycated hemoglobin. If unacceptably high plasma glucose levels (e.g., 8 mmol/L or more before meals) persist the use of orally given hypoglycemic agents (a sulfonylurea agent or metformin or both) is indicated. Temporary insulin therapy may be needed during intercurrent illness, surgery or pregnancy. Long-term insulin therapy is recommended in patients with continuing symptoms or hyperglycemia despite treatment with diet modification and orally given hypoglycemic agents. The risk of pancreatitis may be reduced by treating severe hypertriglyceridemia (fasting serum level greater than 10 mmol/L) and atherosclerotic disease through dietary and, if necessary, pharmacologic management of dyslipidemia. Antihypertensive agents are available that have fewer adverse metabolic effects than thiazides and beta-adrenergic receptor blockers. New drugs are being developed that will enhance effective insulin secretion and action and inhibit the progress of complications.

Diuretic-induced hypokalemia

Diuretic therapy is the most common cause of potassium deficiency. Although the extent of potassium deficiency usually does not exceed 200 or 300 mEq, under appropriate circumstances such modest deficiency may have important consequences. Factors that tend to increase the incidence or severity of potassium deficiency in patients who take diuretics include high salt diets, large urine volumes, metabolic alkalosis, increased aldosterone production, and the simultaneous use of two diuretics that act on different sites in the renal tubule. There are many serious complications of potassium deficiency, including cardiac arrhythmias, muscle weakness, rhabdomyolysis, glucose intolerance, and several complications that result directly from increased ammonia production, such as protein and nitrogen wasting and hepatic coma. Emphasized herein are those conditions that impose potential danger in patients with mild hypokalemia. Important factors that identify specific causes of potassium deficiency and its treatment are discussed briefly.

The application of potassium selective electrodes in the intensive care unit

Recent advances in analytical electrochemistry have provided highly selective potassium ion exchangers and robust polymeric membranes that can be used to measure the potassium activity in plasma or whole blood. The relationship between the activity measurement and the more familiar concentration measurement is explored. The ion selective electrode (ISE) has certain practical advantages and these have been studied in relation to their use in an intensive care unit. The application of these membranes to the continuous measurement of potassium in the circulation is discussed.

The effect of frusemide used for post-prostatectomy irrigation on total body potassium

The effects of 2 techniques of bladder irrigation on total body potassium have been compared. The results show that a net decrease was associated with both methods. This was marginally greater (0.1 greater than P greater than 0.05) in the group which underwent a forced diuresis using frusemide with a fluid load. This group received some potassium supplements without which it is possible that the decrease would have been greater. It is concluded that this regime cannot be overtly criticised for its potential loss of potassium.

Potassium status of patients with cirrhosis

Whole body potassium measurements were performed on 55 cirrhotic patients in different stages of the disease. They included 34 with alcoholic cirrhosis, 10 with cryptogenic cirrhosis, eight with chronic active hepatitis, and three with haemochromatosis. Serial measurements were carried out in 21 patients. The findings of this study indicate that: (1) the aetiology of the cirrhosis is important in determining the potassium status of cirrhotics, most alcoholics being depleted; (2) ascites and decompensation are usually associated with potassium depletion but compensated cirrhotics may also be depleted even when not receiving diuretics; (3) the initial potassium status, whether a cirrhotic be decompensated or not, is difficult to alter in the short term (six months). Marked changes in potassium status can occur in alcoholic patients studied over longer periods.