RESUMO
Coffee administration has been shown to increase maximum voluntary contraction and muscular endurance. However, no study has addressed the association between daily consumption of coffee with muscular function. This cross sectional study aimed to investigate the association between frequency of coffee consumption (CC) in daily life and muscle strength among a population of working adult men. This cross sectional study included men (n = 516, mean age: 47.1) who participated in an annual health examination conducted in Sendai. The monthly frequency of coffee consumed was reported by a brief-type self-administered dietary history questionnaire. Leg extension power (LEP) was measured as an index of muscle strength. Subjects were divided into tertile levels according to CC. Analysis of covariance was used to examine the relation between the tertile levels of CC and LEP. After adjustment for potential confounders (including all lifestyle factors), the adjusted means (95% confidence interval) of LEP across the tertiles of CC were 17.4 (16.6 - 18.1) for the lowest tertile, 17.9 (17.4 - 18.5) for the mid tertile, and 18.9 (18.3 - 19.5) for the highest tertile (p for trend = 0.007). Higher frequency of monthly coffee consumption was associated with higher muscle strength.
RESUMO
Aging is associated with decreased skeletal muscle function. Increased levels of advanced glycation end products (AGEs) in skeletal muscle tissue are observed with advancing age and in diabetes. Although serum AGE level is negatively associated with grip strength in elderly people, it is unknown whether this association is present in adult males. To determine the relationship between AGE accumulation in tissue and muscle strength and power among Japanese adult men. Skin autofluorescence (AF) (a noninvasive method for measuring tissue AGEs), grip strength (n = 232), and leg extension power (n = 138) were measured in Japanese adult men [median (interquartile range) age, 46.0 (37.0, 56.0) years]. After adjustment for potential confounders, the adjusted means [95% confidence interval (CI)] for grip strength across the tertiles of skin AF were 44.5 (43.2, 45.9) kg for the lowest tertile, 42.0 (40.6, 43.3) kg for the middle tertile, and 41.7 (40.3, 43.1) kg for the highest tertile (P for trend < 0.01). Moreover, the adjusted geometric means (95% CI) of leg extension power across the tertiles of skin AF were 17.8 (16.6, 19.1) W/kg for the lowest tertile, 17.5 (16.4, 18.7) W/kg for the middle tertile, and 16.0 (14.9, 17.1) W/kg for the highest tertile (P for trend = 0.04). Among Japanese adult men, participants with higher skin AF had lower muscle strength and power, indicating a relationship between AGE accumulation and muscle strength and power. A long-term prospective study is required to clarify the causality.
