Insulin resistance and brain-derived neurotrophic factor levels in chronic kidney disease.
BACKGROUND
Insulin resistance is a frequent abnormality in chronic kidney disease (CKD) appearing in early stages. Factors known to promote insulin resistance in CKD patients include disorders of ion and acid-base equilibrium and circulating uremia toxins. Recent research has focused on the central nervous system as the source of the brain-derived neurotrophic factor (BDNF). The aim of our work was to study plasma BDNF concentrations in stage 3 and 4 CKD patients in relationship with insulin resistance and distribution of adipose tissue.


METHODS
Plasma BDNF concentrations were measured in a study group of 31 patients, including a subgroup of 20 non-diabetic subjects. Additionally dual-energy X-ray absorptiometry (DXA) was performed. Homeostatic model assessment of insulin resistance (HOMA-IR) and homeostatic model assessment of B-cell function (HOMA-beta) indices were calculated.


RESULTS
Two separate analyses were performed. In the first analysis performed in all 31 CKD patients, there were no correlations between BDNF and: body mass index (BMI), android, gynoid fat distribution, HOMA-IR and HOMA-beta. In the second analysis performed in 20 CKD patients without diabetes, BDNF was negatively related to gynoid fat (Rs = -0.47, P = 0.034) and women revealed significantly lower levels of BDNF than men (P = 0.046). Normotensive patients disclosed significantly higher BDNF levels than hypertensive patients in the whole CKD group (P = 0.039) and in the non-diabetic subgroup (P = 0.028). No correlations between BDNF and eGFR were found.


CONCLUSIONS
Female sex and arterial hypertension are associated with lower BDNF plasma concentration in CKD patients.
Department of Nephrology, Transplantology and Internal Diseases, Pomeranian Medical University, Poland malgorzata.marchelek@gmail.com.
Małgorzata
M
Marchelek-Myśliwiec
Department of Nephrology, Transplantology and Internal Diseases, Pomeranian Medical University, Poland.
Ewa
E
Cichocka
Department of Biochemistry and Medical Chemistry, Pomeranian Medical University, Poland.
Violetta
V
Dziedziejko
Department of Nephrology, Transplantology and Internal Diseases, Pomeranian Medical University, Poland.
Gra Ż Yna
GŻ
Dutkiewicz
Department of Nephrology, Transplantology and Internal Diseases, Pomeranian Medical University, Poland.
Joanna
J
Stępniewska
Department of Biochemistry and Medical Chemistry, Pomeranian Medical University, Poland.
Krzysztof
K
Safranow
Department of Medical Analytics, Pomeranian Medical University, Poland.
Marta
M
Budkowska
Department of Medical Analytics, Pomeranian Medical University, Poland.
Daria
D
Sałata
Department of Endocrinology, Pomeranian Medical University, Poland.
Anhelli
A
Syrenicz
Department of Pathology, Pomeranian Medical University, Poland.
Bogusław
B
Machaliński
Department of Nephrology, Transplantology and Internal Diseases, Pomeranian Medical University, Poland.
Kazimierz
K
Ciechanowski
D050154:Adiposity; D015992:Body Mass Index; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications; D003928:Diabetic Nephropathies / Q000150:complications / Q000453:epidemiology / Q000378:metabolism / Q000503:physiopathology; D015536:Down-Regulation; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications; D007328:Insulin / Q000097:blood / Q000378:metabolism; D007333:Insulin Resistance; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000378:metabolism; D050152:Intra-Abdominal Fat / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011044:Poland / Q000453:epidemiology; D051436:Renal Insufficiency, Chronic / Q000150:complications / Q000453:epidemiology / Q000378:metabolism* / Q000503:physiopathology; D012307:Risk Factors; D012720:Severity of Illness Index; D012727:Sex Characteristics
D019208:Brain-Derived Neurotrophic Factor; D007328:Insulin; C579455:BDNF protein, human
Renal disease; clinical studies; endocrinology