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Biomedical subjects

F X Pi-Sunyer

Publications and source records attributed to F X Pi-Sunyer.

159 records · Page 9Linked to original sources

Neural control of counter-regulatory events during glucopenia in man.

The effect of autonomic denervation on the metabolic and hormonal responses during intracellular glucopenia in man was investigated. 2-Deoxy-d-glucose (2 DG), a competitive inhibitor of glucose metabolism, was administered intravenously to nine normal volunteers and to five patients, three with complete cervical cord transection (C-6) and two with idiopathic orthostatic hypotension. Before, during, and after a 20 min infusion of 2 DG (50 mg/kg) plasma concentrations of glucose, lactate, FFA, total catecholamines, immunoreactive insulin (IRI), human growth hormone (HGH), and cortisol were determined for periods up to 150 min. In control subjects, the initial elevation of FFA, glucose. HGH, and cortisol corresponded with the rise in total catecholamines, with maximal levels attained at 60 min, lactate rose at a slower rate, reaching peak levels at 150 min: although no change in IRI was noted. In contrast, 2 DG-induced glucopenic stress in the autonomic denervated subjects was characterized by no detectable catecholamine release or significant rise in glucose, FFA, lactate, or IRI. However, HGH and cortisol responses in four of the five patients were of a similar or greater magnitude than controls.These studies demonstrate that the integrity of the sympathoadrenomedullary axis is essential for the counter-regulatory response to intracellular glucopenia in man. Cortisol and HGH have no apparent role in these events.

Adrenal Medulla↗

A review of long-term studies evaluating the efficacy of weight loss in ameliorating disorders associated with obesity.

Obesity leads to and exacerbates many serious disorders, including hypertension, dyslipidemia, cardiovascular disease, non-insulin-dependent diabetes mellitus, gallbladder disease, respiratory dysfunction, gout, and osteoarthritis. Many short-term studies have shown that weight loss can ameliorate or, in some cases, reverse such disorders. Fewer long-term studies-defined as those whose combined acute intervention and follow-up phases extend for at least 1 year-of the therapeutic benefits of weight loss on specific disorders have been undertaken. Those long-term studies that have been performed tend to confirm the results of briefer studies. Even when weight loss has been comparatively modest or some degree of weight regain has occurred, weight loss is generally associated with a decrease in risk factors and the alleviation of clinical symptoms.

Cardiovascular Diseases↗

Obesity treatment: examining the premises.

Five basic premises underlie the recommendation that obese persons should lose weight: (1) obesity is physically unhealthy; (2) in obese persons, weight loss improves physical health; (3) long-term weight loss is possible; (4) the benefits of weight loss exceed the costs; and (5) weight loss is superior to or can add incrementally to the effects of alternative methods of improving the health and happiness of obese persons. Although the data are occasionally ambiguous, they generally support these premises. Obesity apparently causes increased morbidity and decreased longevity, even after controlling for many plausible confounding factors. Clinical studies consistently show that weight loss reduces morbidity. No adequate data exist on which to evaluate the effects of weight loss on mortality among obese persons. Additional data are needed, but long-term weight loss seems possible, although such losses remain difficult to maintain. A crude estimate is that about 20% of obese persons who attempt to lose weight can achieve and maintain a clinically meaningful weight loss. The short-term health and psychologic costs of gradual weight loss are minor, manageable, and easily surpassed by the short-term health and psychologic benefits. Long-term effects of weight loss on mortality are difficult to judge, and further research is needed. Weight loss can add incrementally to the effects of alternative methods to improve health and happiness among obese persons. Thus, these "alternatives" are better termed "complementary approaches," and their use need not preclude attempts at weight loss. Finally, we provide several guidelines to help practitioners assist obese persons in making reasonable informed decisions about weight loss.

Journal Article↗

Obesity: determinants and therapeutic initiatives.

There are several possible determinants of obesity, including impaired thermogenesis and the differential utilization of fuels in different tissues. Whereas hypometabolism may initiate obesity in some people, once obese, individuals tend to manifest a higher resting metabolic rate because of their greater fat-free mass, exhibit an impaired thermic response to food, and expend more calories than lean individuals for equivalent amounts of activity. As a result, over a 24-h period, obese people generally expend more energy than lean people. A second determinant of obesity is related to fuel utilization and suggests that those predisposed to be obese may have an innate insulin resistance in muscle, leading to decreased uptake, oxidation, and storage of glucose in this tissue. As a result, the glucose is shunted to adipose tissue, where it is stored. With regard to treatment of obesity, emphasis on increased energy expenditure through the inclusion of reasonable amounts of activity is essential. However, this must always be combined with restraint in caloric intake.

Energy Intake↗