Body Heat Storage and Entropy in Sickle Cell Anaemia

Abstract

Background: Sickle cell anaemia patients (SCAP) exhibit a higher basal metabolic rate (BMR) compared to non-sickle cell counterparts (NSCP), attributed to increased cardiac workload and erythropoietic activity.
Objectives: This study compared oxygen consumption rate (VO₂), metabolic heat production (M), BMR, resting energy expenditure (REEp), heat losses (radiation, convection, evaporation, respiration), and estimated changes in heat storage (ΔH) and entropy (ΔS) in SCAP and NSCP.
Methods: Forty-two adult males (21 SCAP, 21 NSCP) were studied. Physical and blood pressure parameters, arterial oxygen saturation (SPO₂), skin temperature (Tsk), and VO₂ were measured. Haematological, oxidative stress (malondialdehyde), and thyroid hormone (triiodothyronine) levels were analyzed.
Results: SCAP showed lower haemoglobin, SPO₂, and triiodothyronine but higher white blood cell count, oxidative stress, heart rate, and skin temperature. VO₂, M, BMR, REEp, ΔH, and ΔS were significantly elevated in SCAP (p < 0.05–0.001). Heat losses via radiation, convection, and respiration were also higher in SCAP. ΔH correlated positively with cardiovascular and oxidative stress markers and negatively with haemoglobin and SPO₂.
Conclusion: SCAP exhibit higher ΔH, ΔS, and metabolic rates due to cardiovascular, haematological, and metabolic compensations. These findings highlight the energy-costly nature of sickle cell anaemia and its impact on thermoregulation.