Obesity-related parameters in carriers of some BDNF genetic variants may depend on daily dietary macronutrients intake

Some common single-nucleotide polymorphisms of the brain-derived neurotrophic factor (BDNF) gene have been associated not only with the neurodegenerative diseases but also with some eating disorders. The aim of this study was to assess the possible differences in the obesity-related and glucose metabolism parameters between some BDNF genotypes', that may depend on the daily energy and macronutrients intake. In 484 adult participants we performed the anthropometric measurements, body composition analysis, and body fat distribution. The daily dietary intake was assessed using the 3-day food intake diaries. Blood glucose and insulin concentrations were measured at fasting and during oral glucose tolerance tests. Moreover, the visceral adipose tissue/subcutaneous adipose tissue (VAT/SAT) ratio and homeostatic model assessment of insulin resistance were calculated. We noted that participants carrying the GG genotype had lower skeletal muscle mass and fat free mass (FFM) when carbohydrate intake was > 48%, whereas they presented higher fat-free mass (FFM), and surprisingly higher total cholesterol and LDL-C concentrations when daily fiber intake was > 18 g. Moreover, in these subjects we noted higher waist circumference, BMI, and fasting glucose and insulin concentrations, when > 18% of total daily energy intake was delivered from proteins, and higher VAT content and HDL-C concentrations when > 30% of energy intake was derived from dietary fat. Our results suggest that glucose homeostasis and obesity-related parameters in carriers of some common variants of BDNF gene, especially in the GG (rs10835211) genotype carriers, may differ dependently on daily energy, dietary macronutrients and fiber intake.

A new morphologic index for the evaluation of renal biopsies in lupus nephritis

BACKGROUND

Various morphologic indices for the evaluation of renal biopsies in lupus nephritis have been developed, of which the most successful have been the NIH Activity Index (AI) and Chronicity Index (CI). We wished to develop a biopsy index from standard light and immunofluorescence (IF) material that would correlate yet more closely with clinical and outcome parameters than the current indices, and be applicable to both treated and untreated cases.

METHODS

A cohort of 71 patients with lupus nephritis who had initial renal biopsies (Bx1) with systematic second biopsies (Bx2) at six months after induction therapy was studied, with a large number of light microscopic and IF variables evaluated. These were examined statistically to choose the combinations of variables with the highest overall correlations with clinical and outcome parameters.

RESULTS

The adopted biopsy index comprised four elements: Glomerular Activity Index (GAI), a modification of the standard AI with the addition of glomerular monocytes and elimination of interstitial inflammation; Tubulointerstitial Activity Index (TIAI), evaluating several tubular epithelial and inflammatory components, including interstitial inflammation, but excluding tubular atrophy; Chronic Lesions Index, a modification of the standard CI, with the addition of glomerular scars; IF Index (IFI), a semiquantitative index of IF staining for six standard antisera for glomerular capillary, mesangial, tubulointerstitial, and vascular elements. The Biopsy Index showed a statistically higher correlation with clinical and outcome parameters than the NIH AI (P = 0.0170), the NIH CI (P = 0.0009), or their combination (P = 0.0444). At Bx1, comparisons between correlation coefficients for the appropriate AI or CI value and for the Biopsy Index, were: anti-DNA antibodies (0.30 vs. 045), serum creatinine (SCr; 0.33 vs. 0.48), proteinuria (0.22 vs. 0.36), hemoglobin (-0.21 vs. -0.45), and final renal function (0.22 vs. 0.40). Spearman rank correlations showed similar superiority for outcome parameters: doubling of SCr (0.1810 vs. 0.3018) and end-stage renal disease (0.0529 vs. 0.1925). The same improvement of correlations was seen at Bx2 for most parameters, particularly doubling of SCr (0.2716 vs. 0.4753).

CONCLUSIONS

The Biopsy Index and/or its components show better correlations with clinical and outcome parameters than the standard AI and CI and other similar indices.