G5 Doctoral dissertation (article)
Menopause, physical activity, and whole-body metabolism with an emphasis on resting energy expenditure, fat oxidation, and serum metabolome (2023)
Menopaussin ja fyysisen aktiivisuuden yhteydet lepoenergiankulutukseen, rasvan käytön tehoon ja muutoksiin seerumin metabolomissa

Karppinen, J. (2023). Menopause, physical activity, and whole-body metabolism with an emphasis on resting energy expenditure, fat oxidation, and serum metabolome [Doctoral dissertation]. University of Jyväskylä. JYU dissertations, 636. http://urn.fi/URN:ISBN:978-951-39-9575-1

JYU authors or editors

Publication details

All authors or editors: Karppinen, Jari

eISBN: 978-951-39-9575-1

Journal or series: JYU dissertations

eISSN: 2489-9003

Publication year: 2023

Number in series: 636

Number of pages in the book: 1 verkkoaineisto (153 sivua, 49 sivua useina numerointijaksoina, 22 numeroimatonta sivua)

Publisher: University of Jyväskylä

Place of Publication: Jyväskylä

Publication country: Finland

Publication language: English

Persistent website address: http://urn.fi/URN:ISBN:978-951-39-9575-1

Publication open access: Openly available

Publication channel open access: Open Access channel

Abstract

Menopause is thought to impair cardiometabolic health, while physical activity is believed to promote it. This PhD thesis investigated the associations between these two exposures and resting energy expenditure, fat oxidation at rest and during exercise, and changes in the serum metabolome. The thesis also examined the relationship between fat oxidation and blood glucose regulation abilities. The data came from four studies. The longitudinal ERMA study measured serum metabolites with nuclear magnetic resonance spectroscopy from 218 women who were in perimenopause and postmenopause stages (with a median follow-up of 14 months). During the follow-up period, 35 women began using menopausal hormone therapy. The other three studies were cross-sectional and measured resting energy expenditure and fat oxidation at rest and during exercise with indirect calorimetry. The EsmiRs study recruited 42 women (aged 52–58 years) representing different menopause stages. The resting energy expenditure data were supplemented with data from 17 women in the Calex study (aged 42–58 years). The FITFATTWIN study included 23 pairs of monozygotic male twins (aged 32–37 years). Cotwins of 10 pairs were discordant for physical activity over the past 3 years. EsmiRs and FITFATTWIN participants also underwent oral glucose tolerance testing. Based on the results, menopause was associated with increased apolipoprotein B-containing lipoprotein particle number and changes in system biomarkers indicative of overnutrition and declining metabolic health. The changes in metabolite levels were partially explained by shifts in the sex hormone levels. Menopausal hormone therapy improved the apolipoprotein B/A-I ratio. Menopause status or serum sex hormone levels were not associated with resting energy expenditure or fat oxidation. Physical activity discordant cotwins also did not differ in these measures. However, higher physical activity was associated with higher peak fat oxidation during exercise in middle-aged women. Neither resting nor peak fat oxidation indicated better glycemic control or insulin sensitivity. Therefore, menopause may increase cardiometabolic risk by altering the serum metabolome rather than by decreasing resting energy expenditure or fat oxidation capacity. Physical activity may improve fat oxidation capacity during exercise in middle-aged women but without necessarily increasing the ability to regulate blood glucose levels.

Keywords: menopause; physical training; physical activity; energy consumption (metabolism); rest; metabolism; metabolic products; lipid metabolism; glucose metabolism; doctoral dissertations

Free keywords:  menopause; physical activity; energy metabolism; metabolomics

Contributing organizations

Related projects

Ministry reporting: Yes

VIRTA submission year: 2023