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Coffee and caffeine consumption in relation to sex hormone-binding globulin and risk of type 2 diabetes in postmenopausal women.

Goto A, Song Y, Chen BH, Manson JE, Buring JE, Liu S - Diabetes (2010)

Bottom Line: Caffeinated coffee was positively associated with SHBG but not with sex hormones.In contrast, neither decaffeinated coffee nor tea was associated with SHBG or sex hormones.The association was largely attenuated after further adjusting for SHBG (OR 0.71 [95% CI 0.31-1.61]; P for trend = 0.47).

View Article: PubMed Central - PubMed

Affiliation: Department of Epidemiology, Center for Metabolic Disease Prevention, University of California, Los Angeles, USA.

ABSTRACT

Objective: Coffee consumption has been inversely associated with type 2 diabetes risk, but its mechanisms are largely unknown. We aimed to examine whether plasma levels of sex hormones and sex hormone-binding globulin (SHBG) may account for the inverse association between coffee consumption and type 2 diabetes risk.

Research design and methods: We conducted a case-control study nested in the prospective Women's Health Study (WHS). During a median follow-up of 10 years, 359 postmenopausal women with newly diagnosed type 2 diabetes were matched with 359 control subjects by age, race, duration of follow-up, and time of blood draw.

Results: Caffeinated coffee was positively associated with SHBG but not with sex hormones. Multivariable-adjusted geometric mean levels of SHBG were 26.6 nmol/l among women consuming ≥4 cups/day of caffeinated coffee and 23.0 nmol/l among nondrinkers (P for trend = 0.01). In contrast, neither decaffeinated coffee nor tea was associated with SHBG or sex hormones. The multivariable-adjusted odds ratio (OR) of type 2 diabetes for women consuming ≥4 cups/day of caffeinated coffee compared with nondrinkers was 0.47 (95% CI 0.23-0.94; P for trend = 0.047). The association was largely attenuated after further adjusting for SHBG (OR 0.71 [95% CI 0.31-1.61]; P for trend = 0.47). In addition, carriers of rs6259 minor allele and noncarriers of rs6257 minor allele of SHBG gene consuming ≥2 cups/day of caffeinated coffee had lower risk of type 2 diabetes in directions corresponding to their associated SHBG.

Conclusions: Our findings suggest that SHBG may account for the inverse association between coffee consumption and type 2 diabetes risk among postmenopausal women.

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Related in: MedlinePlus

Estimated plasma SHBG and risk of type 2 diabetes in women according to caffeinated coffee consumption. A: The geometric mean SHBG levels adjusted for matching factors, smoking status, physical activity, family history of diabetes, alcohol use, total calories, and BMI from quadratic spline model (solid curve) with pointwise 95% confidence limits (dashed curves). B: The OR of type 2 diabetes from quadratic conditional logistic spline model adjusted for matching factors, smoking status, physical activity, family history of diabetes, alcohol use, total calories, and BMI (solid curve) with pointwise 95% confidence limits (dashed curves). C: The multivariate-adjusted OR of type 2 diabetes from quadratic conditional logistic spline model with further adjustment for plasma SHBG.
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Figure 1: Estimated plasma SHBG and risk of type 2 diabetes in women according to caffeinated coffee consumption. A: The geometric mean SHBG levels adjusted for matching factors, smoking status, physical activity, family history of diabetes, alcohol use, total calories, and BMI from quadratic spline model (solid curve) with pointwise 95% confidence limits (dashed curves). B: The OR of type 2 diabetes from quadratic conditional logistic spline model adjusted for matching factors, smoking status, physical activity, family history of diabetes, alcohol use, total calories, and BMI (solid curve) with pointwise 95% confidence limits (dashed curves). C: The multivariate-adjusted OR of type 2 diabetes from quadratic conditional logistic spline model with further adjustment for plasma SHBG.

Mentions: Caffeinated coffee and caffeine intakes were positively associated with plasma SHBG levels but not with sex hormones (Table 2 and Table 3). For caffeinated coffee, the multivariate-adjusted geometric mean levels of plasma SHBG were 26.6 nmol/l (95% CI 18.9–37.4) in women consuming ≥4 cups/day and 23.0 nmol/l (16.5–32.0) in nondrinkers (P for trend = 0.01). For caffeine, the multivariate-adjusted geometric mean levels of plasma SHBG were 26.6 nmol/l (19.0–37.4) in women consuming >500 mg/day and 22.9 nmol/l (16.5–32.0) in women consuming ≤50 mg/day (P for trend = 0.02) (Table 2). We found similar results using quadratic spline models that imposed smooth dose-response relations (Table 2 and Fig. 1A). The spline plots indicated that heavy drinkers of caffeinated coffee (>2 cups/day) were associated with higher levels of plasma SHBG (Fig. 1A). In contrast, decaffeinated coffee and tea intakes were not associated with plasma SHBG levels and sex hormone levels (Table 3).


Coffee and caffeine consumption in relation to sex hormone-binding globulin and risk of type 2 diabetes in postmenopausal women.

Goto A, Song Y, Chen BH, Manson JE, Buring JE, Liu S - Diabetes (2010)

Estimated plasma SHBG and risk of type 2 diabetes in women according to caffeinated coffee consumption. A: The geometric mean SHBG levels adjusted for matching factors, smoking status, physical activity, family history of diabetes, alcohol use, total calories, and BMI from quadratic spline model (solid curve) with pointwise 95% confidence limits (dashed curves). B: The OR of type 2 diabetes from quadratic conditional logistic spline model adjusted for matching factors, smoking status, physical activity, family history of diabetes, alcohol use, total calories, and BMI (solid curve) with pointwise 95% confidence limits (dashed curves). C: The multivariate-adjusted OR of type 2 diabetes from quadratic conditional logistic spline model with further adjustment for plasma SHBG.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3012180&req=5

Figure 1: Estimated plasma SHBG and risk of type 2 diabetes in women according to caffeinated coffee consumption. A: The geometric mean SHBG levels adjusted for matching factors, smoking status, physical activity, family history of diabetes, alcohol use, total calories, and BMI from quadratic spline model (solid curve) with pointwise 95% confidence limits (dashed curves). B: The OR of type 2 diabetes from quadratic conditional logistic spline model adjusted for matching factors, smoking status, physical activity, family history of diabetes, alcohol use, total calories, and BMI (solid curve) with pointwise 95% confidence limits (dashed curves). C: The multivariate-adjusted OR of type 2 diabetes from quadratic conditional logistic spline model with further adjustment for plasma SHBG.
Mentions: Caffeinated coffee and caffeine intakes were positively associated with plasma SHBG levels but not with sex hormones (Table 2 and Table 3). For caffeinated coffee, the multivariate-adjusted geometric mean levels of plasma SHBG were 26.6 nmol/l (95% CI 18.9–37.4) in women consuming ≥4 cups/day and 23.0 nmol/l (16.5–32.0) in nondrinkers (P for trend = 0.01). For caffeine, the multivariate-adjusted geometric mean levels of plasma SHBG were 26.6 nmol/l (19.0–37.4) in women consuming >500 mg/day and 22.9 nmol/l (16.5–32.0) in women consuming ≤50 mg/day (P for trend = 0.02) (Table 2). We found similar results using quadratic spline models that imposed smooth dose-response relations (Table 2 and Fig. 1A). The spline plots indicated that heavy drinkers of caffeinated coffee (>2 cups/day) were associated with higher levels of plasma SHBG (Fig. 1A). In contrast, decaffeinated coffee and tea intakes were not associated with plasma SHBG levels and sex hormone levels (Table 3).

Bottom Line: Caffeinated coffee was positively associated with SHBG but not with sex hormones.In contrast, neither decaffeinated coffee nor tea was associated with SHBG or sex hormones.The association was largely attenuated after further adjusting for SHBG (OR 0.71 [95% CI 0.31-1.61]; P for trend = 0.47).

View Article: PubMed Central - PubMed

Affiliation: Department of Epidemiology, Center for Metabolic Disease Prevention, University of California, Los Angeles, USA.

ABSTRACT

Objective: Coffee consumption has been inversely associated with type 2 diabetes risk, but its mechanisms are largely unknown. We aimed to examine whether plasma levels of sex hormones and sex hormone-binding globulin (SHBG) may account for the inverse association between coffee consumption and type 2 diabetes risk.

Research design and methods: We conducted a case-control study nested in the prospective Women's Health Study (WHS). During a median follow-up of 10 years, 359 postmenopausal women with newly diagnosed type 2 diabetes were matched with 359 control subjects by age, race, duration of follow-up, and time of blood draw.

Results: Caffeinated coffee was positively associated with SHBG but not with sex hormones. Multivariable-adjusted geometric mean levels of SHBG were 26.6 nmol/l among women consuming ≥4 cups/day of caffeinated coffee and 23.0 nmol/l among nondrinkers (P for trend = 0.01). In contrast, neither decaffeinated coffee nor tea was associated with SHBG or sex hormones. The multivariable-adjusted odds ratio (OR) of type 2 diabetes for women consuming ≥4 cups/day of caffeinated coffee compared with nondrinkers was 0.47 (95% CI 0.23-0.94; P for trend = 0.047). The association was largely attenuated after further adjusting for SHBG (OR 0.71 [95% CI 0.31-1.61]; P for trend = 0.47). In addition, carriers of rs6259 minor allele and noncarriers of rs6257 minor allele of SHBG gene consuming ≥2 cups/day of caffeinated coffee had lower risk of type 2 diabetes in directions corresponding to their associated SHBG.

Conclusions: Our findings suggest that SHBG may account for the inverse association between coffee consumption and type 2 diabetes risk among postmenopausal women.

Show MeSH
Related in: MedlinePlus