Neuromuscular electrical stimulation after cardiovascular surgery mitigates muscle weakness in older individuals with diabetes.

BACKGROUND: Cardiovascular surgery leads to postsurgical muscle weakness, probably because of muscle proteolysis and peripheral nerve dysfunction, which are augmented by aging and diabetes mellitus. OBJECTIVE: We examined the effect of neuromuscular electrical stimulation (NMES) on postsurgical muscle weakness in older individuals with diabetes mellitus. METHODS: We conducted a multicentre, randomized, controlled trial, and screened consecutive patients with diabetes who underwent cardiovascular surgery for eligibility (age ≥ 65 years). Those included were randomly assigned to the NMES or the sham group. The primary outcome was the percent change in isometric knee extension strength (%ΔIKES) from preoperative to postoperative day 7. Secondary outcomes were the percent change in usual (%ΔUWS), maximum walking speed (%ΔMWS), and grip strength (%ΔGS). A statistician who was blinded to group allocation used intention-to-treat analysis (student t test). RESULTS: Of 1151 participants screened for eligibility, 180 (NMES, n = 90; sham, n = 90) were included in the primary analysis. %ΔIKES was significantly lower in the NMES than sham group (NMES: mean -2%, 95% confidence interval [CI] -6 to 1; sham: -13%, 95% CI -17 to -9, p < 0.001). Among the secondary outcomes, %ΔMWS was significantly lower and %ΔUWS and %ΔGS were lower, although not significantly, in the NMES than sham group. CONCLUSIONS: A short course of NMES (< 1 week) mitigated postsurgical muscle weakness and functional decline in older persons with diabetes mellitus. NMES could be recommended as a part of postsurgical rehabilitation in older people with diabetes mellitus, especially those with a low functional reserve.

Maximal calf circumference reflects calf muscle mass measured using magnetic resonance imaging.

BACKGROUND: Calf circumference (CC) has been used as a surrogate for calf muscle mass, which facilitates venous blood return to the heart through active skeletal muscle. However, the correlation between CC and calf muscle mass has not been extensively examined. This study aimed to examine the relationship between CC and calf muscle mass considering differences in sex and physique in elderly individuals. METHODS: A total of 124 community-dwelling elderly individuals ≥60 years of age (61 men, mean [±SD] age 74.3 ± 5.7 years) were enrolled. Maximal CC was measured using a tape measure with the subject supine. The cross-sectional area of skeletal muscle tissues was measured using magnetic resonance imaging from the point of greatest calf circumference to 5 cm proximal and distal. Calf muscle mass was calculated by multiplying the area of each slice by slice thickness (5 mm). RESULTS: CC was strongly correlated with calf muscle mass in male and female subjects (male: r = 0.908, P < 0.001; female: r = 0.892, P < 0.001). Multiple regression analysis revealed that CC and body mass index (BMI) were independent associate factors of calf muscle mass. The following estimation formulae were derived: (male) calf muscle mass (cm3) = 47.82 × CC (cm)-12.50 × BMI (kg/m2) -732.80; (female) calf muscle mass (cm3) = 32.23 × CC (cm) -4.85 × BMI (kg/m2) -429.94. CONCLUSIONS: A strong correlation was found between CC and calf muscle mass according to magnetic resonance imaging. Sex differences and BMI should be considered for accurate estimation of calf muscle mass using CC.

Skeletal Muscle Pump Function Is Associated With Exercise Capacity in Patients With Heart Failure.

BACKGROUND: Skeletal muscle pump function may play a key role in maintaining cardiac output (CO), because of the lack of cardiac contractility reserve during incremental exercise in heart failure (HF) patients. We aimed to investigate the relationship between lower leg pump function and surrogate measures of CO during cardiopulmonary exercise testing (CPX) in HF patients.Methods and Results:Consecutive cardiac patients referred for CPX had their lower leg ejection fraction (LgEF) measured using strain gauge plethysmography as a marker of skeletal muscle pump function. We analyzed 88 patients, including 65 HF patients and 23 control subjects. Unlike the control subjects, LgEF correlated with peak oxygen consumption (V̇O2) and peak oxygen (O2) pulse (peak V̇O2: r=0.280, P=0.024; peak O2 pulse: r=0.540, P<0.001) in HF patients. Significant relationships among LgEF, peak V̇O2, and peak O2 pulse were observed in HF patients with reduced EF (peak V̇O2: r=0.367, P=0.026; peak O2 pulse: r=0.658, P<0.001), whereas LgEF in HF patients with preserved EF showed a weak correlation only with peak O2 pulse (r=0.407, P=0.032). LgEF was selected as an independent determinant of peak V̇O2 (ß=0.187, P=0.036) and peak O2 pulse (ß=0.520, P<0.001) in HF patients. CONCLUSIONS: Lower leg skeletal muscle function may contribute to exercise capacity through an indirect mechanism on cardiac function in HF.

Predictive impact of daily physical activity on new vascular events in patients with mild ischemic stroke.

BACKGROUND: Daily physical inactivity is associated with a substantially increased risk of cardiovascular events. However, the target level of daily physical activity remains unclear. AIM: We aimed to evaluate the impact of physical activity on long-term vascular events in patients with mild ischemic stroke. METHODS: We designed a single hospital-based prospective observational study and studied 166 ischemic stroke patients (mean age: 63.9 ± 9.2) who had a modified Rankin Scale 0-1. We measured the daily step count as a variable of the daily physical activity after three-months from the stroke onset. Other clinical characteristics including age, body mass index, blood pressure, blood laboratory tests, vascular function and medications were also assessed. The primary outcomes were hospitalization due to stroke recurrence, myocardial infarction, angina pectoris and peripheral artery disease. Survival curves were calculated by a Kaplan-Meier survival analysis, and the hazard ratios for recurrences were determined by univariate and multivariate Cox proportional hazards regression models. RESULTS: After a median follow-up periods of 1332 days, 34 vascular events (23 stroke recurrences, 11 coronary artery disease) and 7 drop-outs occurred, and the remaining patients were divided into two groups: the without recurrence group (n = 125) and the with recurrence group (n = 34). The daily step count was lower in the nonsurvivor group than in the survivor group. Univariate and multivariate Cox proportional hazards analyses revealed that the daily step counts was independent predictors of new vascular events. A daily step count cutoff value of 6025 steps per day was determined by analyzing the receiver-operating characteristics that showed a sensitivity of 69.4% and a specificity of 79.4%. The Kaplan-Meier survival curves after a log-rank test showed a significantly lower event rate in the more than 6025 steps per day group compared with the less than 6025 steps per day group (P = 0.0002). The positive and negative predictive values of less than 6025 steps were 38.0% and 91.6%, respectively. CONCLUSION: Our data indicate that daily physical activity evaluated by step counts may be useful for forecasting the prognosis in patients with mild ischemic stroke. Daily step counts of approximately 6000 steps per day may be an initial target level for reducing new vascular events.

[Clinical course of recovery from cognitive dysfunction in a patient with anti-N-methyl-D-aspartate receptor encephalitis].

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is an autoimmune disorder, which occurs commonly in young women and is often associated with ovarian teratomas. We report the case of a patient with this disease, who exhibited cognitive deficits, and describe the clinical course of recovery from cognitive dysfunction. A 29-year-old right-handed woman suffered from chills and fever for 7 days prior to admission to hospital, and complained that she could not understand the content of TV programs. Following admission to hospital, she was found to have an ovarian teratoma and underwent oophorectomy. She was diagnosed with anti-NMDA receptor encephalitis based on the presence of antibodies in the serum and cerebrospinal fluid. She subsequently experienced phases with disturbance of consciousness and involuntary movement, and then moved into the gradual recovery phase 3 months after onset. Cerebral SPECT revealed a left-dominant decrease of blood flow in the prefrontal regions bilaterally. Neuropsychological examination 3 months after onset revealed frontal lobe syndrome comprising executive dysfunction, decreased spontaneity, and environmental dependency in addition to recent memory deficits. Approximately 6 months after onset, recent memory impairments and environmental dependency were resolved, and a gradual improvement in spontaneity and executive function was seen. One year after onset, the patient had regained independence and ability to self-care, and returned to her workplace. Our observations suggest that patients with anti-NMDA receptor encephalitis may recover from frontal lobe syndrome, including executive dysfunction and decreased spontaneity, slower than patients with other cognitive dysfunctions do.

Urine output and resultant osmotic water shift are major determinants of plasma sodium level in syndrome of inappropriate antidiuretic hormone secretion.

Although various formulas predicting plasma sodium level ([Na]) are proposed for correction of hyponatremia, it seems that an anticipated [Na] frequently exceeds or falls below the measured [Na], especially in syndrome of inappropriate antidiuretic hormone secretion (SIADH). The causative factors of the fluctuation have never been investigated clearly. The aim of this study was to identify the determining factors for accurate prediction of [Na] by comparing data from previously proposed formulas and a novel osmotic compartment model (O-C model). The O-C model, which simulates the amounts of osmoles in extracellular and intracellular fluids, can estimate resultant osmotic water shift (OWS) and [Na]. The accuracy of representative formulas was verified in a point-to-point study using blood and urine samples obtained every 4 hours from 9 patients. Among 161 measurement points, a large fluctuation of urine volume and urine sodium level was observed. The gap between anticipated and measured [Na] in the widely used Adrogue-Madias formula was -0.5 ± 0.1 mEq/L/4 h (mean ± standard error), showing a marked tendency to underestimate [Na]. The gap in the O-C model including OWS was 0.1 ± 0.1 mEq/L/4 h, and that in the O-C model eliminating OWS was 1.9 ± 0.2 mEq/L/4 h, indicating that measurement of urine output and estimation of resulting OWS are essential for a superior prediction of [Na] in SIADH. A simulation study with the O-C model including OWS unveiled a distinctive correction pattern of [Na] dependent on the urine volume and urine sodium level, providing a useful choice for the proper type and rate of infusion.

Central diabetes insipidus and hypothalamic hypothyroidism associated with aceruloplasminemia.

Aceruloplasminemia is a rare autosomal recessive disease first reported by Miyajima et al. (Neurology 37: 761-767, 1987); it is clinically characterized by diabetes mellitus, retinal degeneration and neurological abnormalities, such as cerebellar ataxia, extrapyramidal signs and dementia. Aceruloplasminemia is caused by mutations in the ceruloplasmin gene, which results in the absence of serum ceruloplasmin and iron overload in the brain, liver, pancreas and other organ tissues. However, little is known about endocrine diseases associated with aceruloplasminemia. We report herein a case of aceruloplasminemia accompanied by central diabetes insipidus and hypothalamic hypothyroidism.