Is obesity associated with lower body temperatures? Core temperature: a forgotten variable in energy balance

Landsberg, Lewis; Young, James B.; Leonard, William R.; Linsenmeier, Robert A.; Turek, Fred W.

doi:10.1016/j.metabol.2009.02.017

Cited by 74 publications

(75 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our finding of an association between obesity and reduced body temperature in dogs is consistent with the suggestion made by Landsberg et al 5 that obesity may result from an increase in metabolic efficiency achieved by a regulated lowering of body temperature. That is, a lowering of body temperature may allow the storage of energy that would otherwise have been spent in thermogenic processes necessary for the maintenance of a higher level of body temperature.…”

Section: Discussionsupporting

confidence: 93%

“…If the lowering of body temperature follows the development of obesity, then it cannot possibly cause it. However, if the lowering of body temperature precedes or accompanies the development of obesity, then the hypothesis of Landsberg et al 5 might be correct. It is important, therefore, to conduct a prospective longitudinal study that starts at birth and that allows the monitoring of body temperature before the inception of obesity.…”

Section: Discussionmentioning

confidence: 97%

“…Landsberg et al 5 pointed out that discussions of the balance between energy intake and energy expenditure in the control of body weight almost always ignore the major energetic role played by homeothermy. As homeothermy can account for 2/3 or more of energy expenditure in mammals and birds, 6,7 a small reduction in body temperature could yield great energy savings, thus favoring energy storage and the consequent development of obesity.…”

Section: Introductionmentioning

confidence: 99%

“…Thus, a chronic lowering of body temperature might be a causal factor of the metabolic syndrome. 5 There has been surprisingly little research on the possible connection between body core temperature and obesity. Rising et al 8 found an association of lower body temperatures with lower metabolic rates across individuals, but they were unable to demonstrate the expected association between lower metabolic rates and obesity.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Association between obesity and reduced body temperature in dogs

et al. 2010

View full text Add to dashboard Cite

Background: Industrialized nations are currently experiencing an obesity epidemic, the causes of which are not fully known. One possible mechanism of enhanced energy efficiency that has received almost no attention is a reduction in the metabolic cost of homeothermy, which could be achieved by a modest lowering of body core temperature. We evaluated the potential of this obesity-inducing mechanism in a canine model of the metabolic syndrome. Methods: We compared the rectal temperature of lean dogs and obese dogs by (a) conducting cross-sectional measurements in 287 dogs of many breeds varying greatly in body size, (b) conducting longitudinal measurements in individual dogs over 7-10 years and (c) tracking rectal temperature of lean and obese dogs at 3-h intervals for 48 consecutive hours in the laboratory. Results: We found that larger dogs have lower rectal temperatures than smaller dogs and that, for the same body mass, obese dogs have lower rectal temperatures than lean dogs. The results were consistent in the cross-sectional, longitudinal and aroundthe-clock measurements. Conclusion: These findings document an association between obesity and reduced body temperature in dogs and support the hypothesis that obesity in this and other species of homeotherms may result from an increase in metabolic efficiency achieved by a regulated lowering of body temperature.

show abstract

Section: Discussionsupporting

confidence: 93%

Section: Discussionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Association between obesity and reduced body temperature in dogs

et al. 2010

View full text Add to dashboard Cite

show abstract

“…However, in our study, patients who might suffer with hypothalamic damage by tumor invasion or treatment including surgery and/or radiotherapy were excluded. Furthermore, it has been reported that obesity is associated with BT or serum thyroid hormone levels (23,24). Table 5 BT and thyroid parameters according to BMI, menopausal status, and other pituitary hormone deficiency in CeH.…”

Section: Clinical Study Y Hirata and Others L-t 4 Therapy For Centralmentioning

confidence: 99%

Median-lower normal levels of serum thyroxine are associated with low triiodothyronine levels and body temperature in patients with central hypothyroidism

Hirata

Fukuoka

Iguchi

et al. 2015

European Journal of Endocrinology

View full text Add to dashboard Cite

Objective: Although it has been recommended that serum free thyroxine (FT 4 ) levels should be targeted to middle-upper normal levels during levothyroxine (L-T 4 ) replacement therapy in patients with central hypothyroidism (CeH), the rationale has not been clarified. Methods: A retrospective single-center study enrolled 116 patients with hypothyroidism (CeH, nZ32; total thyroidectomy (Tx), nZ22; primary hypothyroidism (PH), nZ33; and control benign thyroid nodule (C), nZ29). The patients had received L-T 4 therapy at the Kobe University Hospital between 2003 and 2013. They were stratified according to serum FT 4 level (R1.10 or !1.10 ng/dl), and body temperature (BT), serum free triiodothyronine (FT 3 ) levels, FT 3 /FT 4 ratio, and lipid profiles were compared. The effect of GH replacement therapy on thyroid function was also analyzed. Results: FT 3 levels and FT 3 /FT 4 ratios were significantly lower in patients with CeH than in patients with PH (P!0.05) or C (P!0.05). In patients with FT 4 !1.10 ng/dl, BT was significantly lower in patients with CeH (PZ0.002) and Tx (PZ0.005) than in patients with PH, whereas no differences were found in patients with FT 4 R1.10 ng/dl. In patients with CeH, FT 3 levels were higher in those with GH replacement therapy (PZ0.018). Conclusion: In CeH, patients with median-lower normal levels of serum FT 4 exhibited lower serum FT 3 levels and lower BT. These results support the target levels of serum FT 4 as middle-upper normal levels during L-T 4 replacement therapy in patients with CeH.

show abstract

Defining Usual Oral Temperature Ranges in Outpatients Using an Unsupervised Learning Algorithm

Ley,

Heath,

Hastie

et al. 2023

JAMA Intern Med

View full text Add to dashboard Cite

ImportanceAlthough oral temperature is commonly assessed in medical examinations, the range of usual or “normal” temperature is poorly defined.ObjectiveTo determine normal oral temperature ranges by age, sex, height, weight, and time of day.Design, Setting, and ParticipantsThis cross-sectional study used clinical visit information from the divisions of Internal Medicine and Family Medicine in a single large medical care system. All adult outpatient encounters that included temperature measurements from April 28, 2008, through June 4, 2017, were eligible for inclusion. The LIMIT (Laboratory Information Mining for Individualized Thresholds) filtering algorithm was applied to iteratively remove encounters with primary diagnoses overrepresented in the tails of the temperature distribution, leaving only those diagnoses unrelated to temperature. Mixed-effects modeling was applied to the remaining temperature measurements to identify independent factors associated with normal oral temperature and to generate individualized normal temperature ranges. Data were analyzed from July 5, 2017, to June 23, 2023.ExposuresPrimary diagnoses and medications, age, sex, height, weight, time of day, and month, abstracted from each outpatient encounter.Main Outcomes and MeasuresNormal temperature ranges by age, sex, height, weight, and time of day.ResultsOf 618 306 patient encounters, 35.92% were removed by LIMIT because they included diagnoses or medications that fell disproportionately in the tails of the temperature distribution. The encounters removed due to overrepresentation in the upper tail were primarily linked to infectious diseases (76.81% of all removed encounters); type 2 diabetes was the only diagnosis removed for overrepresentation in the lower tail (15.71% of all removed encounters). The 396 195 encounters included in the analysis set consisted of 126 705 patients (57.35% women; mean [SD] age, 52.7 [15.9] years). Prior to running LIMIT, the mean (SD) overall oral temperature was 36.71 °C (0.43 °C); following LIMIT, the mean (SD) temperature was 36.64 °C (0.35 °C). Using mixed-effects modeling, age, sex, height, weight, and time of day accounted for 6.86% (overall) and up to 25.52% (per patient) of the observed variability in temperature. Mean normal oral temperature did not reach 37 °C for any subgroup; the upper 99th percentile ranged from 36.81 °C (a tall man with underweight aged 80 years at 8:00 am) to 37.88 °C (a short woman with obesity aged 20 years at 2:00 pm).Conclusions and RelevanceThe findings of this cross-sectional study suggest that normal oral temperature varies in an expected manner based on sex, age, height, weight, and time of day, allowing individualized normal temperature ranges to be established. The clinical significance of a value outside of the usual range is an area for future study.

show abstract

Is obesity associated with lower body temperatures? Core temperature: a forgotten variable in energy balance

Cited by 74 publications

References 57 publications

Association between obesity and reduced body temperature in dogs

Association between obesity and reduced body temperature in dogs

Median-lower normal levels of serum thyroxine are associated with low triiodothyronine levels and body temperature in patients with central hypothyroidism

Defining Usual Oral Temperature Ranges in Outpatients Using an Unsupervised Learning Algorithm

Contact Info

Product

Resources

About