Kidney function and glucose metabolism in overweight and obese cats

Body Condition Scores in Cats and Associations with Systolic Blood Pressure, Glucose Homeostasis, and Systemic Inflammation

BACKGROUND

Feline obesity is the most common nutritional disease in cats. This study aimed to investigate the differences between systolic blood pressure (SBP) and circulating concentrations of glucose, fructosamine, and serum amyloid-A (SAA) in ideal-weight, overweight, and obese cats.

METHODS

The animals were divided into three groups: ideal-weight (BCS 5, N = 20), overweight (BCS 6, N = 20), and obese cats (BCS ≥ 7, N = 20). SBP, circulating concentrations of glucose, fructosamine, and SAA were evaluated.

RESULTS

The SBP values of the ideal-weight, overweight, and obese cats were 140.0 mmHg, 160.0 mmHg, and 160.0 mmHg, respectively. The blood glucose and fructosamine levels for the ideal, overweight, and obese cats were 104.0 mg/dL and 245.0 µmol/L, 123.0 mg/dL and 289.0 µmol/L, and 133.0 mg/dL and 275.0 µmol/L, respectively, for each group. The SAA values were <5 ug/mL in all the groups. The SBP values of the cats with ideal BCS were significantly lower compared to overweight (p = 0.019) and obese (p = 0.001) cats. The blood glucose values of obese cats were higher than those of ideal-weight cats (p = 0.029). There was no statistical difference between the groups for fructosamine and SAA.

CONCLUSIONS

Obese cats had significantly higher SBP and blood glucose concentrations than ideal-weight cats, showing the effect of BSC on these parameters.

Short-term evaluation of renal markers in overweight adult cats

BACKGROUND

Obesity has been proposed as an independently risk factor for chronic kidney disease (CKD) in people, but its role in feline kidney function is unknown.

OBJECTIVE

Obesity has been proposed as an independent risk factor for chronic kidney disease (CKD) in people, but its role in feline kidney function is unknown. This study prospectively evaluated the effect of overweight on the concentration of symmetric dimethylarginine (SDMA) and creatinine in a cohort of healthy cats.

METHODS

Forty healthy adult cats were included, 14 with a body condition score (BCS) = 5 and 26 with a BCS > 5. Cats were examined every 6 months, for up to 12 months. SDMA and creatinine were measured at baseline and follow-up.

RESULTS

No effect was found for time of follow-up (p = 0.072), overweight (p = 0.9442) or their interaction (p = 0.902) on SDMA, though a significant effect was found for age (p < 0.001) [older cats showing higher SDMA] and sex (p = 0.007) [male cats showing higher SDMA]. Regarding creatinine, no effect for time (p = 0.671), age (p = 0.061), overweight (p = 0.319) or the latter's interaction (p = 0.386) were found.

CONCLUSIONS

In the short term, markers of renal function did not show an association with overweight. The role of obesity in feline kidney function still warrants further evaluation.

Trimester-Specific Serum Fructosamine in Association with Abdominal Adiposity, Insulin Resistance, and Inflammation in Healthy Pregnant Individuals

This study aimed to (1) characterize the variations in serum fructosamine across trimesters and according to pre-pregnancy BMI (ppBMI), and (2) examine associations between fructosamine and adiposity/metabolic markers (ppBMI, first-trimester adiposity, leptin, glucose homeostasis, and inflammation measurements) during pregnancy. Serum fructosamine, albumin, fasting glucose and insulin, leptin, adiponectin, interleukin-6 (IL-6), and C-reactive protein (CRP) concentrations were measured at each trimester. In the first trimester, subcutaneous (SAT) and visceral (VAT) adipose tissue thicknesses were estimated by ultrasound. In the 101 healthy pregnant individuals included (age: 32.2 ± 3.5 y.o.; ppBMI: 25.5 ± 5.5 kg/m2), fructosamine concentrations decreased during pregnancy whereas albumin-corrected fructosamine concentrations increased (p < 0.0001 for both). Notably, fructosamine concentrations were inversely associated with ppBMI, first-trimester SAT, VAT, and leptin (r = −0.55, r = −0.61, r = −0.48, r = −0.47, respectively; p < 0.0001 for all), first-trimester fasting insulin and HOMA-IR (r = −0.46, r = −0.46; p < 0.0001 for both), and first-trimester IL-6 (r = −0.38, p < 0.01). However, once corrected for albumin, most of the correlations lost strength. Once adjusted for ppBMI, fructosamine concentrations were positively associated with third-trimester fasting glucose and CRP (r = 0.24, r = 0.27; p < 0.05 for both). In conclusion, serum fructosamine is inversely associated with adiposity before and during pregnancy, with markers of glucose homeostasis and inflammation, but the latter associations are partially influenced by albumin concentrations and ppBMI.

Ultrasonographic evaluation of adrenal gland size in two body weight categories of healthy adult cats

OBJECTIVES

Adrenal gland size and its association with body weight have been rarely evaluated in cats. This study was undertaken to assess the association between feline body weight and adrenal gland thickness, and to propose reference intervals (RIs) for adrenal gland thickness in healthy cats.

METHODS

This was a cross-sectional study in which 39 healthy cats were included. The cats were divided into two weight categories, classified as ⩽4.0 kg and >4-8 kg of ideal body weight (with 13 and 26 cats in each group, respectively), which took into consideration the body condition score of the cats. All cats underwent an ultrasound examination that was taken from a subcostal position. Maximum dorsoventral thicknesses of the left (MTL) and right (MTR) adrenal glands were measured in a sagittal plane. RIs were obtained for the maximum thickness (MT), which included the MTLs and MTRs of each cat. RIs with the 90% confidence intervals were calculated according to American Society for Veterinary Clinical Pathology guidelines on RIs.

RESULTS

No statistical differences for adrenal gland thickness were observed between the left and right (P = 0.543) adrenal glands or between male and female cats (P = 0.943). Mean MT was significantly greater in the group of cats weighing >4-8 kg compared with the group of cats weighing ⩽4 kg (3.7 ± 0.6 vs 3.2 ± 0.4 mm; P <0.005). The lower limit of the RI for MT was 2.4 mm (range 2.2-2.6 mm) in the group weighing ⩽4 kg and 2.6 mm (range 2.4-2.8 mm) in the group weighing >4-8 kg. The upper limit of the RI for MT was 3.9 mm (range 3.7-4.1 mm) in the group of cats weighing ⩽4 kg and 4.8 mm (range 4.6-5.1 mm) in the group of cats weighing >4-8 kg.

CONCLUSIONS AND RELEVANCE

The use of RIs based on two group sizes allows for a more accurate ultrasonographic evaluation of adrenal gland thickness in cats. The maximum normal adrenal gland thickness is lower in smaller cats (3.9 mm for those weighing ⩽4 kg and 4.8 mm for those weighing >4-8 kg).