Glucose-induced thermogenesis in patients with small cell lung carcinoma. Before and after inhibition of tumour growth by chemotherapy

Alterations in glucose metabolism in non-endocrine disease: potential implication for wasting

Diseases like sepsis, AIDS and cancer can induce an increase in endogenous glucose production. Sepsis and cancer induce insulin resistance whereas increased insulin sensitivity is found in AIDS. Non-oxidative glucose disposal is increased in sepsis and cancer but normal in AIDS. These differences in glucose metabolism between these three diseases characterized by wasting preclude energy-requiring changes in glucose metabolism as the common denominator for wasting in all three diseases. Moreover, the energy requirements of the changes in glucose metabolism induced by cancer and sepsis are rather small. Consequently, alterations in glucose metabolism are pathophysiological epiphenomena rather than a cause of wasting in disorders like sepsis, cancer and AIDS.

Glucose-induced thermogenesis in patients with small cell lung carcinoma. The effect of acute beta-adrenergic inhibition

Seven patients with histologically verified small cell lung carcinoma were given an oral glucose load of 75 g on two occasions to examine the effect of glucose on whole body and forearm thermogenesis with and without acute beta-adrenergic inhibition with propranolol. Whole body energy expenditure was measured by the open circuit ventilated hood system. Forearm blood flow was measured by venous occlusion strain-gauge plethysmography. The uptake of oxygen in the forearm was calculated as the product of the forearm blood flow and the difference in arteriovenous oxygen concentration. The glucose-induced thermogenesis in the 120 min following the glucose load was significantly reduced by beta-adrenergic inhibition with approximately 50% from 63.9 +/- 5.8 kJ 120 min-1 (mean +/- SE) to 27.8 +/- 9.8 kJ 120 min-1 (P < 0.01). Almost the entire reduction took place from 60 to 120 min (P < 0.005). The integrated glucose-induced forearm oxygen uptake in the period 60-120 min following the glucose load was significantly reduced after beta-adrenergic inhibition from 103 +/- 28 mumol 100 g-1 60 min-1 to 29 +/- 29 mumol 100 g-1 60 min-1 (P < 0.05). The noreadrenaline concentration in the arterial blood was not increased in the baseline period compared to healthy elderly; it increased following the glucose load while there was no demonstrable increase in adrenaline concentration in the two experiments. It is suggested that these patients have increased sensitivity of the beta-adrenergic receptors and an early facultative component of the glucose-induced thermogenesis in part takes place in the forearm.

Inter-relationships between single carbon units' metabolism and resting energy expenditure in weight-losing patients with small cell lung cancer. Effects of methionine supply and chemotherapy

The one-carbon unit metabolism was investigated in 8 weight-losing patients with small cell carcinoma of the lung (SCLC). At diagnosis, 6 of the 8 patients had elevated formiminoglutamic acid (FIGLU) excretion after a histidine load, suggesting a lack of one-carbon units. In accordance, a significant decrease of FIGLU excretion was observed in the patients after oral administration of DL-methionine for 4 days. The elevated FIGLU excretion was positively correlated to weight loss prior to diagnosis and negatively correlated to serum albumin at time of diagnosis. After 3 months of combination chemotherapy, FIGLU excretion was reduced in all patients except 1, who had progressive disease. Despite the elevated FIGLU excretions, all patients had normal blood folate levels. The resting energy expenditure (REE) was recorded in 7 patients, and a significant, positive correlation was observed between pretreatment FIGLU excretion and REE, although the REE measured in this group of patients was within the normal range. These data demonstrate an increased demand of "active" one-carbon units in energy consumption in a group of weight-losing cancer patients. The one-carbon unit deficit was reconditioned by oral administration of the one-carbon unit donor DL-methionine.