Serum levels of retinol binding protein 4 in women with different levels of adiposity and glucose tolerance / Níveis séricos da proteína carreadora do retinol 4 em mulheres com diferentes níveis de adiposidade e tolerância à glicose

Objective Retinol-binding protein 4 (RBP4) is an adipokine responsible for vitamin A (retinol) transportation. Studies associated RBP4 increased levels with severity of type 2 diabetes mellitus (T2DM) and insulin resistance (IR). The study aimed to quantify RBP4 serum standards in women with a wide range of body mass index (BMI) and glucose tolerance level. Subjects and methods: Cross-sectional study was performed with 139 women divided into three groups: Group 1 (lean-control, n = 45) and Group 2 (obese, n = 53) with normal glucose tolerance and group 3 (obese with T2DM, n = 41), called G1, G2 and G3. Were assessed clinical, biochemical, anthropometric and body composition parameters. Results According to data analysis, we obtained in G1 higher RBP4 levels (104.8 ± 76.8 ng/mL) when compared to G2 (87.9 ± 38 ng/mL) and G3 (72.2 ± 15.6 ng/mL) levels. Also, were found: in G1 positive correlations of RBP4 with BMI (r = 0.253), glycated hemoglobin (r = 0.378) and fasting insulin (r = 0.336); in G2 with glycated hemoglobin (r = 0.489); in G3 with glycated hemoglobin (r = 0.330), fasting glucose (r = 0.463), HOMA-IR (r = 0.481). Conclusions Although RBP4 have shown lower levels in diabetic and obese, a strong correlation with HOMA-IR index highlights that, in our study, there is growing IR when there is an increasing in RBP4 levels. .

Objetivo A proteína carreadora do retinol 4 (RBP4) é uma adipocina responsável pelo transporte de vitamina A (retinol). Estudos associam os níveis aumentados de RBP4 com a gravidade do diabetes melito tipo 2 (DM2) e resistência à insulina (RI). O objetivo deste estudo foi investigar como esses níveis se comportam em mulheres com ampla variação do índice de massa corporal (IMC) e tolerância à glicose. Sujeitos e métodos: Estudo transversal realizado com 139 mulheres, divididas em três grupos: Grupo 1 (controles-magras; n = 45) e Grupo 2 (obesas; n = 53), com tolerância normal à glicose; Grupo 3 (obesas DM2; n = 41), denominados G1, G2 e G3. Foram avaliados parâmetros clínicos, bioquímicos, antropométricos e composição corporal. Resultados De acordo com a análise dos dados, obtivemos em G1 maiores níveis de RBP4 (104,8 ± 76,8 ng/mL) em comparação ao G2 (87,9 ± 38 ng/mL) e G3 (72,2 ± 15,6 ng/mL). Também foram encontradas correlações positivas entre RBP4 e IMC (r = 0,253), hemoglobina glicada (r = 0,378) e insulinemia de jejum (r = 0,336); em G2 com hemoglobina glicada (r = 0,489); G3 com hemoglobina glicada (r = 0,330), insulinemia de jejum (r = 0,463) e HOMA-IR (r = 0,481). Conclusões Embora a RBP4 tenha apresentado níveis menores em pacientes diabéticas e obesas, a forte correlação com o índice HOMA-IR deixa claro que, em nosso estudo, há crescente RI quando os níveis dessa proteína também são crescentes. .

Função renal de pacientes de unidade de terapia intensiva: creatinina plasmática e proteína carreadora do retinol urinário / Renal function of intensive care unit patients: plasma creatinine and urinary retinol-binding protein

OBJETIVOS: A avaliação precoce da disfunção renal usando marcadores usuais não supre uma indicação quer da sensitividade e da especificidade da disfunção renal de pacientes críticos. Seriam desejáveis marcadores mais específicos e sensíveis para a detecção precoce de um processo fisiopatológico renal em fase inicial. A proteína carreadora do retinol urinário poderia ser um método alternativo para avaliação precoce da função renal destes pacientes. MÉTODOS: O estudo acompanhou 100 pacientes em terapia intensiva e avaliou suas variáveis clinicas e laboratoriais, incluindo a dosagem de creatinina plasmática e proteina carreadora do retinol urinário e as variáveis demográficas. RESULTADOS: A amostra foi caracterizada por pacientes geriátricos (63,4±15,6 anos), homens (68 por cento), sendo 53 por cento cirúrgicos. Análise estatística mostrou associação entre creatinina plasmática e as seguintes variáveis: gênero (p=0,026), idade (p=0,038), uso de medicação vasoativa (p=0,003), proteinúria (p=0,025), escore Acute Physiological Chronic Health Evaluation (APACHE) II (p=0,000), uréia (p=0,000), potássio (p=0,003) clearance de creatinina estimado (p=0,000). A proteína carreadora do retinol urinário correlacionava-se com outras variáveis: peso usa de ventilação invasiva (p=0,000), uso de medicamentos antinfamatórios não-esteróides (p=0,018), uso de medicação vasoativa (p=0,021), temperatura alta (>37,5ºC) (p=0,005), proteinúria (p=0,000), bilirubinúria (p=0,004), fluxo urinário (p=0,019), pressão diastólica mínima (p=0,032), pressão sistólica mínima (p=0,029), APACHE II (p=0.000), creatinina (p=0,001), uréia (p=0,001) e clearance de creatinina estimado (p=0,000). A proteína carreadora do retinol urinário também tende a ser associada com doença renal anterior, vasculopatias e neoplasias. Na análise univariada, a fração de excreção de sódio se correlacionou com creatinina plasmática e proteina carreadora do retinol urinário. CONCLUSÃO: A proteina...

OBJECTIVES: The early assessment of renal dysfunction using common markers does not provide either a sensitive or specific indication of renal dysfunction in critically ill patients. More specific and sensitive markers are desirable for the early detection of an initial renal pathophysiological process. Urinary retinol-binding protein could be an alternative method to early evaluation of renal function in these patients. METHODS: This study followed-up 100 critical care patients and assessed their clinical and laboratory variables, including plasma creatinine and urinary retinol-binding ratio, and demographic variables. RESULTS: The sample was characterized by geriatric (63.4±15.6 years), male (68 percent), being 53 percent surgical patients. Statistical analysis showed association between plasma creatinine and the following variables: gender (p-0.026), age (p-0.038), use of vasoactive drugs (p-0.003), proteinuria (p-0.025), Acute Physiological Chronic Health Evaluation (APACHE) II score (p-0.000), urea (p-0.000), potassium (p-0.003) and estimated creatinine clearance (p-0.000). Urinary retinol-binding protein was correlated with more variables: weight, use of invasive ventilation (p-0.000), use of nonsteroidal antiinflammatory drugs (p-0.018), use of vasoactive drugs (p-0.021), high temperature (>37.5ºC) (p-0.005), proteinuria (p-0.000), bilirubinuria (p-0.004), urinary flow (p-0.019), minimal diastolic pressure (p-0.032), minimal systolic pressure (p-0.029), APACHE II (p-0.000), creatinine (p-0.001), urea (p-0.001), estimated creatinine clearance (p-0.000). Urinary retinol-binding protein also tended to associate with previous renal disease, vasculopathy and neoplasm. Sodium excretion fraction correlated with plasma creatinine and urinary retinol-binding protein in univariate analysis. CONCLUSIONS: Urinary retinol-binding protein might be considered in clinical practice as a better marker regarding diagnostic performance in patients...

Effect of dietary protein on vitamin A levels in plasma and liver of hypervitaminotic-A rats.

Level of vitamin A increased in plasma and liver in hypervitaminotic A albino rats fed normal quantity of protein in diet. In low protein fed state vitamin A level in liver increased due to accumulation of vitamin A and lack of carrier protein with an associated decrease of plasma vitamin A. In high protein fed rats the level of vitamin A in plasma increased due to enhanced transport while in liver it decreased. The results indicate that for normal transport of vitamin A adequate plasma protein level is essential.

The effect of oral contraceptives on protein metabolism.

The effect on protein and amino acid metabolism of combined oral contraceptives (OC) containing 150 micrograms of laevonorgestrel and 30 micrograms of ethinyl oestradiol was studied in a group of 34 healthy non-lactating women. This was compared to an identical study conducted in another group of 19 subjects who used IUCDs for contraception, and also in two other groups of subjects who were given an additional multivitamin preparation on a daily basis (29 subjects) and on the days when OC was not taken (29 subjects). Assessments were made prior to, and during the third week of the 4th, 7th, and the 13th cycles of OC treatment. Results indicated that the ceruloplasmin and retinol binding protein underwent significant increases with OC usage, while sex hormone binding globulin concentration, on the other hand, remained unaffected. At the same time, a significant reduction of several of the plasma amino acid and plasma albumin concentrations was observed, suggesting that the increase in the visceral and other types of protein concentrations previously noted was due to increased hepatic protein synthesis rather than increased breakdown or excretion as result of OC intake. Interesting biochemical alterations and metabolic effects previously observed may well be related to this altered synthesis and release of proteins and/or protein binders as well as induction of certain metabolic enzymes from the liver.