Right-to-Work Laws and the Crumbling of American Public Health by Deborah Wallace & Rodrick Wallace

Author:Deborah Wallace & Rodrick Wallace
Language: eng
Format: epub
Publisher: Springer International Publishing, Cham

Chapter 1 has these observations: Fat is stored in specialized cells, the adipocytes. One of the most important findings of the 1990s is the glandular nature of adipocytes; they secrete hormones that shape the physiological processes of the body, from influencing the biological clock (Antonijevic et al. 1998) to directing whether T1 or T2 helper cells dominate (Lord et al. 1998). The best studied of these hormones is leptin.

…Leptin is released by fat cells after a meal (Houseknecht et al. 1998) and signals to the alimentary biological clock that the person has eaten and needs to eat no more. Leptin also influences and is influenced by the sleep/wake biological clock, peaking during the night, whereas the adrenal hormone cortisol peaks during the day (Casaneuva and Dieguez 1999; Houseknecht et al. 1998). Leptin and cortisol maintain a dynamic balance; people with central abdominal obesity secrete cortisol faster than normal weighted people but clear it faster (Lottenberg et al. 1998). Cortisol is one of the adrenal hormones secreted in response to stress, especially to threatening stresses, a sign of the triggering of the generalized stress reaction of “fight or flight” (Newcomer et al. 1998). The complementary circadian cycles of leptin and cortisol balance the need for sleep and for alertness against threats to survival. Furthermore, cortisol is accepted as a general marker of the status of the HPA axis (Ahlborg et al. 2002).…

Recent work suggests links between stress, its attendant neurophysiological changes, and overweight/obesity. For example, people suffering from chronic stress-related sleep pattern disruption metabolize their food differently from non-sufferers. The calories are channeled more into fat storage, and the fat is particularly deposited in the central abdominal area (Spiegel et al. 1999). The second round of Whitehall Studies revealed that hierarchical stress (stress imposed by lack of control over one’s circumstances) was associated with higher BMI, central abdominal fat deposition, and higher rates of coronary heart disease and associated mortality (Brunner et al. 1997). The lower the occupational grade of the civil servants within the Whitehall cohort, the higher the prevalence of overweight/obesity, central abdominal fat deposition, and CHD.

Researchers in several other nations replicated and extended the results of the Whitehall studies. Middle-aged Swedish men with markers of HPA axis activation were found to have higher prevalence of overweight/obesity and central abdominal fat deposition (Rosmond and Bjorntorp 1998). Occupational class was found to associate strongly with overweight/obesity and waist-to-hip ratio (a measure of central abdominal fat deposition) among adults in several countries, including the United States and Japan (Marmot et al. 1998; Nakamura et al. 1998). Laboratory animal studies showed that leptin receptors are part of the hypothalamus (Iqbal et al. 2000). This suggests that fat cells send signals to the HPA, especially to the hypothalamus which, among other functions, regulates both the independent but related sleep/wake and eating biological clocks. (pp. 16–17)

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