Perioperative Dietary Restriction of Carbohydrates in the Management of Blood Glucose Levels in Patients Undergoing Total Knee Replacement

Approximately 75% of the US population over 65 years has prediabetes or diabetes. Despite current evidence for the efficacy of carbohydrate restriction in managing blood glucose, this practice has not been implemented as part of routine perioperative blood sugar management. We hypothesize that a carbohydrate reduced hospital diet (CRD) of 135 g/d may improve blood sugar levels following total knee arthroplasty (TKA) compared to a non-carbohydrate reduced hospital diet (NCRD).

We randomized non-insulin-dependent prediabetic and diabetic patients undergoing TKA to either an NCRD or a CRD. Sixty-four patients were enrolled in the study and 2 were excluded, leading to 62 patients in the final analysis. The NCRD group included 14 females (47%) and 16 males (53%), with mean age of 68.5 years (±6.3 years). The CRD group included 16 females (50%) and 16 males (50%), with mean age of 68.0 years (±8.0 years). For hemoglobin A _1C, the NCRD group had mean 5.8% (±0.6%) and the CRD group had mean 5.7% (±0.8%). For body mass index, the NCRD group had mean 29.3 kg/m ² (±6.3 kg/m²) and the CRD group 32.7 kg/m ² (±5.0 kg/m ²). The primary outcome measure was mean blood glucose.

Mean blood sugar values during hospital stay were significantly lower in the CRD group with 121.5 mg/dL (±17.1 mg/dL) compared to the NCRD group 141.2 mg/dL (±31.3 mg/dL, P = .0031).

Blood sugar levels after surgery can be significantly reduced with a CRD. Further research is necessary to study the effect of reduced blood sugar levels on complications and infection rates following TKA surgery.

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