Quantifying the improvement of surrogate indices of hepatic insulin resistance using complex measurement techniques

We evaluated the ability of simple and complex surrogate-indices to identify individuals from an overweight/obese cohort with hepatic insulin-resistance (HEP-IR). Five indices, one previously defined and four newly generated through step-wise linear regression, were created against a single-cohort sample of 77 extensively characterised participants with the metabolic syndrome (age 55.6±1.0 years, BMI 31.5±0.4 kg/m2; 30 males). HEP-IR was defined by measuring endogenous-glucose-production (EGP) with [6–62H2] glucose during fasting and euglycemic-hyperinsulinemic clamps and expressed as EGP*fasting plasma insulin. Complex measures were incorporated into the model, including various non-standard biomarkers and the measurement of body-fat distribution and liver-fat, to further improve the predictive capability of the index. Validation was performed against a data set of the same subjects after an isoenergetic dietary intervention (4 arms, diets varying in protein and fiber content versus control). All five indices produced comparable prediction of HEP-IR, explaining 39–56% of the variance, depending on regression variable combination. The validation of the regression equations showed little variation between the different proposed indices (r2 = 27–32%) on a matched dataset. New complex indices encompassing advanced measurement techniques offered an improved correlation (r = 0.75, P<0.001). However, when validated against the alternative dataset all indices performed comparably with the standard homeostasis model assessment for insulin resistance (HOMA-IR) (r = 0.54, P<0.001). Thus, simple estimates of HEP-IR performed comparable to more complex indices and could be an efficient and cost effective approach in large epidemiological investigations

Health related quality of life in 2002 and 2015 in patients undergoing hemodialysis:a single center study

Health related quality of life (HRQOL) has become a recognized outcome in studies of the treatment of patients undergoing hemodialysis (HD). The aim of this study was to assess changes in HRQOL reported by two different samples of patients undergoing HD in the same dialysis center in 2002 and 2015. Two samples of patients from the same Danish dialysis center completed the HRQOL questionnaire Kidney Disease Quality of Life version 1.3 in 2002 (n = 71) and 2015 (n = 81), respectively. The associations between KDQOL summery scores and the time frame were analyzed in multivariable regression analyses. The 2015 sample of patients were older compared to the 2002 sample (66 ± 13 vs. 59 ± 16 years, p = 0.003, respectively), they comprised more obese patients (20.6 vs. 3.2%, p = 0.002) and more patients with hypoalbuminemia (66.7 vs. 42.9%, p = 0.006). After confounder adjustment the time period 2015 versus 2002 was not associated with changes in the generic summery scales Physical Component Scale (β 3.9, 95% C

Vitamin D, Surface Electromyography and Physical Function in Uraemic Patients

&lt;i&gt;Background:&lt;/i&gt; Muscle function is impaired in uraemic patients and several causes have been proposed. Deficiency of 25-hydroxyvitamin D (25-OHD), which affects muscle function in non-uraemic patients, may very well also be associated with the myopathy found in these patients. The aim of this study was to investigate the association between 25-OHD and muscle function as well as physical function in chronic kidney disease (CKD) and peritoneal dialysis (PD) patients. &lt;i&gt;Methods:&lt;/i&gt; In this cross-sectional study, 21 adult patients with CKD stage 3–5 and 21 patients treated with PD were included. Standard biochemistry parameters were measured including 25-OHD, 1,25-dihydroxycholecalciferol (1,25-OHD) and parathyroid hormone analysis. Muscle function was determined by 30-second surface electromyography (sEMG) recordings of a right thigh muscle (vastus lateralis) and a second left finger muscle (second dorsal interosseous) under voluntary contractions. Physical function was determined using a 30-second Chair Stand Test and the Short Form 36 quality of life questionnaire. Clinical characteristics were collected from the patient records. &lt;i&gt;Results:&lt;/i&gt; Moderate vitamin 25-OHD deficiency (&lt;40 nmol/l) was measured in 52% of patients with CKD and in 71% of the patients on PD. Severe deficiency (&lt;15 nmol/l) was measured in 14% of patients on PD. There were no significant differences between the CKD and PD patients in terms of sEMG results. 25-OHD was not correlated to any results from the tests of sEMG or physical function. However, a higher sEMG frequency and signal root mean square (RMS) were positively associated with a higher Chair Stand Test score. Time to maximum sEMG frequency was negatively correlated to the Chair Stand Test score (p &lt; 0.05), and positively correlated to the level of comorbidity (p &lt; 0.05). sEMG signal peak-peak amplitude, frequency and RMS were positively correlated to the quality of life scales Physical Function, Role Physical, General Health, Vitality, Social Function, Mental Health, and Physical Component Scale (p &lt; 0.001). &lt;i&gt;Conclusions:&lt;/i&gt; 25-OHD deficiency was prevalent in uraemic patients in the present study. Muscle function as determined using sEMG and the Chair Stand Test was not associated with 25-OHD. The results may be biased by the limited variation in 25-OHD and masked by effects of several other variables in this very sick population.</jats:p