Effects of surgery on free and total 25 hydroxyvitamin D concentrations in dogs

Evaluation of serum 25-hydroxyvitamin D, C-reactive protein, and haptoglobin as biomarkers in dogs newly diagnosed with histoplasmosis

BACKGROUND

Serum 25-hydroxyvitamin (OH)D, C-reactive protein (CRP), and haptoglobin are useful biomarkers in various infectious diseases and inflammatory disorders in dogs, but their utility in histoplasmosis is unknown.

OBJECTIVE

Determine if serum 25(OH)D, CRP, and haptoglobin concentrations are different in dogs with histoplasmosis compared to healthy controls and whether serum globulin, albumin, CRP, or haptoglobin are associated with 25(OH)D concentration.

ANIMALS

Twenty-two client-owned dogs (histoplasmosis, n = 12; controls, n = 10).

METHODS

Prospective case-control study. Dogs with histoplasmosis were categorized as pulmonary, disseminated, or gastrointestinal (GI) tract. Serum 25(OH)D was measured using modified high-performance liquid chromatography (HPLC). Serum CRP and haptoglobin were measured with ELISA assays.

RESULTS

Dogs with histoplasmosis were grouped as disseminated (n = 8) and GI tract (n = 4). No dogs had pulmonary tract involvement alone. Dogs with histoplasmosis (median, interquartile range [IQR]; 11.6 ng/mL, 16.8) had lower serum 25(OH)D concentrations than controls (35.7 ng/mL, 17.6; P < .001). Serum CRP and haptoglobin concentrations were higher in dogs with histoplasmosis (CRP: median, IQR; 63.5 mg/L, 37.1 and haptoglobin: 459.7 mg/dL, 419.6) than controls (CRP: 1.9 mg/L, 2; P < .001 and haptoglobin: 85.5 mg/dL, 106.7; P = .003). Serum 25(OH)D concentration was positively associated with fold change in serum albumin concentration (ρ = 0.77; P < .001), and negatively associated with fold change in serum globulin (ρ = -0.61; P = .003) and CRP concentrations (ρ = -0.56; P = .01).

CONCLUSION AND CLINICAL IMPORTANCE

Assay of serum 25(OH)D, CRP, and haptoglobin could have clinical value in dogs with histoplasmosis.

Serum 25-hydroxyvitamin D concentrations in dogs with coccidioidomycosis and variables associated with extent of clinically evident disease

BACKGROUND

Clinicopathologic variables predictive of disseminated coccidioidomycosis are known in humans but have not been explored in dogs. Serum 25-hydroxyvitamin (OH)D correlates with severity of disease of various etiologies in dogs but its role in coccidioidomycosis is unknown.

OBJECTIVE

Determine whether serum 25(OH)D concentrations are different in dogs with coccidioidomycosis compared with healthy controls and if clinicopathologic variables are associated with extent of disease.

ANIMALS

Thirty-five dogs with coccidioidomycosis (pulmonary, n = 13; disseminated, n = 15; uncharacterized, n = 7), and 25 healthy control dogs.

METHODS

Prospective cohort study. Serum 25(OH)D and C-reactive protein (CRP) concentrations were measured with modified-HPLC and a commercial ELISA kit, respectively.

RESULTS

There was no difference in 25(OH)D concentrations between dogs with coccidioidomycosis (median, interquartile range [IQR]; 31.9 ng/mL, 23.3-49.2) and controls (29.5 ng/mL, 25.6-40.8, P = .73). Serum 25(OH)D concentration was lower in dogs with coccidioidomycosis and IgG titers ≥1:32 than dogs with titers below this cut-off (P = .02). Dogs with IgG titers ≥1:32 were more likely to have disseminated disease (OR, 7.5; 95% CI: 1.1-68; P = .03). Serum CRP concentrations were higher in dogs with IgG titers ≥1:16 (median, IQR; 4474.8 ng/mL, 2885.8-8236.1) than in those below this cut-off (151.2 ng/mL, 30.4-2907.3; P = .02). There was a significant inverse association between serum 25(OH)D and CRP at 25(OH)D concentrations ≤33 ng/mL.

CONCLUSION AND CLINICAL IMPORTANCE

Serum 25(OH)D concentration was lower for dogs with IgG titers ≥1:32, indicating a potential association between semi-quantitative titers and 25(OH)D concentrations in dogs with coccidioidomycosis. IgG titers ≥1:32 yielded higher odds of disseminated disease, but was inadequate as a standalone test to determine form of disease.

Vitamin D metabolism and disorders in dogs and cats

Vitamin D plays an important role in regulating calcium metabolism and in the development and maintenance of skeletal health of companion animals. There is also a growing interest in understanding the role vitamin D plays in non-skeletal health in both human and veterinary patients. This review provides an update of our current understanding of vitamin D biology in dogs and cats and gives an overview of how vitamin D metabolism can be assessed in companion animals. Congenital and acquired vitamin D disorders are then summarised before the review concludes with a summary of recent studies which have explored the role of vitamin D in the development and outcomes of non-skeletal diseases of dogs and cats.

Serum 25-hydroxyvitamin D concentrations and mortality in dogs with blastomycosis

Blastomycosis is a prominent fungal disease in the United States. Vitamin D status has been found to be altered in critical illness and various infectious diseases. The objectives of this study were to compare serum 25-hydroxyvitamin D (25[OH]D) concentrations in dogs with blastomycosis and healthy controls, to assess the change in serum 25(OH)D concentrations in dogs with blastomycosis after 30 days of treatment, and to determine if baseline serum 25(OH)D concentrations in dogs with blastomycosis were associated with in-hospital, 30-day, or end-of-study mortality. In this prospective cohort study, 19 dogs newly diagnosed with blastomycosis had serum 25(OH)D concentrations measured with a commercially available validated radioimmunoassay at the time of diagnosis and 30 days after start of treatment. These values were compared to 24 healthy control dogs. Serum 25(OH)D concentrations at the time of diagnosis were lower in dogs with blastomycosis (median, 203 nmol/L; range, 31-590 nmol/L) than in clinically healthy control dogs (259.5 nmol/L, 97-829 nmol/L; P = 0.01). Despite clinical improvement, there was no significant change in serum 25(OH)D concentrations from baseline to 30-day follow-up. Dogs with baseline serum 25(OH)D concentrations <180.5nmol/L had a greater odds of death during hospitalization (odds ratio [OR], 15.0; 95% confidence interval [CI], 1.4-191.3; P = 0.04) and at 30 days follow-up (OR, 30.0; 95% CI, 2.5-366.7; P = 0.006). These findings highlight the need for further studies evaluating the prognostic value of vitamin D status in dogs with blastomycosis at diagnosis and throughout treatment and remission.

Effects of surgery on free and total 25 hydroxyvitamin D concentrations in dogs

Background

It is unclear whether a low total 25(OH)D concentration is a cause or consequence of illnesses. To address this knowledge gap, studies measuring free and total 25(OH)D during the evolution and resolution of an inflammatory process are required.

Objectives

Serum total and free 25(OH)D concentrations would transiently decline after cruciate surgery in dogs.

Animals

Seventeen client‐owned dogs with a spontaneous cranial cruciate ligament rupture (CCLR).

Methods

A longitudinal cohort study involving the measurement of serum concentrations of total and free 25(OH)D, total calcium, creatinine, albumin, phosphate, C‐reactive protein and plasma ionized calcium, at 1 day before and a median time of 1 and 60 days after surgical treatment of CCLR.

Results

Median serum concentrations of total 25(OH)D before surgery (80.3 nmoL/L [range, 43.5‐137.3]) significantly declined immediately after surgery; (64.8 nmoL/L [range, 36.3‐116.5] 1 day after surgery, P < .005) before increasing to become nonsignificantly different from concentrations before surgery at day 60 after surgery (median 78.0 nmoL/L [range, 24.2‐115.8], P = .14). In contrast, median free 25(OH)D concentrations before surgery (7.6 pg/mL [range, 3.8‐12.2]) significantly increased immediately after surgery (9.2 pg/mL [range, 5.2‐15.7], P < .05) before declining to become nonsignificantly different from before surgery concentrations at day 60 after surgery (median 6.2 pg/mL [range, 4.0‐15.8], P = .37).

Conclusion and Clinical Importance

This study reveals the difficulties of assessing vitamin D status in dogs following elective surgery.