Low BUN can be due to inadequate protein intake, and possibly hypochlorhydria if it impairs protein digestion and availability significantly. Low BUN may also reflect overhydration which would cause a “dilutional” effect.
The elevated total protein could reflect an increase in immunoglobulins and other globulins as well as albumin (which is unlikely to be high if protein intake is insufficient).
Elevated total protein may also be due to dehydration, though dehydration is often reflected with an increased BUN, not a decreased BUN.
- Assess protein needs and intake, most individuals need 0.8-1.5 grams protein/kg body weight.
- Assess fluid needs, most individuals need at least ½ ounce of fluid per pound of body weight (30-35 mL/kg).
- Assess for an acute immune response, increase in other globulins such as sex hormone-binding globulin, thyroid-binding globulin, transferrin, and/or assess for excess inflammation.
- Assess liver and kidney function
- Consider full workup for underlying conditions if current values persist upon repeat blood work.
References:
Busher, Janice T. “Serum Albumin and Globulin.” Clinical Methods: The History, Physical, and Laboratory Examinations, edited by H Kenneth Walker et. al., 3rd ed., Butterworths, 1990.
Higgins, Chris. "Urea and the clinical value of measuring blood urea concentration.” Acutecaretesting. Org, no. August (2016): 1-6.
LabTestsOnline.org. BUN. Total protein, Albumin-Globulin Ratio.