Ontogeny and aging of the distal skin temperature rhythm in humans

Abstract

In circadian terms, human ontogeny is characterized by the emergence of a daily pattern, from a previous ultradian pattern, for most variables during the first 6 months of life. Circadian aging in humans is characterized by a phase advance, accompanied by rhythm fragmentation and flattening. Despite an expanding body of literature focused on distal skin temperature, little information is available about the ontogeny and practically nothing about age-related changes in this rhythm. Thus, the aim was to evaluate the degree of maturation and aging of the circadian pattern of distal skin temperature to identify those parameters that are modified throughout life and could be used to differentiate subjects according to their age. For this, distal skin temperature was measured in 197 volunteers (55 % women), including babies aged 15 days (30 subjects), 1 month (28 subjects), 3 months (31 subjects), and 6 months (10 subjects); young adults aged 19 years (37 subjects); middle-aged persons aged 46 years (27 subjects); older people aged 72 (34 subjects). Circadian system maturation was associated with an increase in amplitude and a reduction in skin temperature during sleep. During adulthood, women showed a more robust pattern (lower fragmentation, and higher night-time temperature, amplitude, circadian function index, and first harmonic relative power); however, these differences were lost with aging, a period of life that was consistently associated with a phase advance of the rhythm. In summary, distal skin temperature pattern can be used as a robust variable to discern between different ages throughout the life.

The Mediating Role of Brown Fat and Skeletal Muscle Measured by 18F‐Fluorodeoxyglucose in the Thermoregulatory System in Young Adults

“…The relationship between Personal‐ET and the WT daily pattern has been widely used in the field of chronobiology . Several studies comparing WT daily patterns in women with obesity versus women with normal weight , young versus older men and women , and men versus women have shown worse patterns (higher variability and higher daytime values) of WT in older participants and participants with obesity . These findings are also in accordance with those of human BAT studies, which showed that people with obesity, older people, and men had lower BAT volume and activity .…”

Chronodisruption: A Poorly Recognized Feature of CKD

“…On the other, CKD causes accelerated aging and some of the factors responsible for this phenotype, such as decreased production of the anti-aging factor Klotho have been identified, as discussed below. Interestingly, aging is associated with altered central and peripheral circadian rhythms, and the sleep-wake cycle [52], leading to a phase advance, rhythm fragmentation and flattening [53]. This may in part be offset by regular physical activity [52].…”

Temperatura corporal do paciente idoso no período pós‑operatório

“…Esse padrão de irresponsividade térmica pode ser atribuído a várias causas, como os distúrbios da termogênese, ou seja, a diminuição do metabolismo basal, da eficiência dos tremores musculares e da vasoconstrição periférica; a redução da produção e sensibilidade à IL-1, as alterações comportamentais e as atividades da vida diária 16 .…”

“…Um estudo realizado com a população idosa na unidade de emergência de um hospital universitário da Alemanha identificou nesse grupo de pacientes valores inferiores da T. axilar quando comparados a outros locais de aferição. Entretanto, outro estudo realizado nas cidades de Múrcia e Toledo, na Espanha, mostra que a aferição da temperatura em locais distais constitui-se um método não invasivo, confiável e confortável para a obtenção de dados de temperatura 16,17 .…”

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