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Differential effect of glycemia on the incidence of hypertension by sex: the epidemiology of diabetes complications study.

Costacou T, Orchard TJ - Diabetes Care (2012)

Bottom Line: A significant interaction was noted between sex and HbA(1c), and separate models were constructed by sex.Multivariably, elevated HbA(1c) was a significant predictor only in men (hazard ratio 1.48 [95% CI 1.28-1.71]).Although hyperglycemia is a risk factor for hypertension, its effect is stronger in men compared with women with type 1 diabetes.

View Article: PubMed Central - PubMed

Affiliation: Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA, USA. costacout@edc.pitt.edu

ABSTRACT

Objective: Diabetes Control and Complications Trial/Epidemiology of Diabetes Intervention and Complications analyses demonstrated that intensive insulin therapy was inversely associated with incident hypertension. We thus sought to confirm these observations and, given sex differences in other type 1 diabetes complications and risk factors, assessed whether any such associations differ by sex.

Research design and methods: Participants of a prospective cohort of childhood-onset type 1 diabetes, free of hypertension at study entry (baseline mean age, 28 years; diabetes duration, 19 years), were selected for study (n = 510). Hypertension incidence was defined as blood pressure >140/90 mmHg or use of hypertension medications in two consecutive visits. Intensive insulin therapy was defined as three or more injections (or pump) and four or more glucose tests daily. Baseline predictors of hypertension were examined using Cox proportional hazards models. Models with time-dependent updated means of baseline significant variables were also constructed.

Results: Hypertension incidence over 18 years of follow-up was marginally higher in men than in women (43.2 vs. 35.4%, P = 0.07). A significant interaction was noted between sex and HbA(1c), and separate models were constructed by sex. Multivariably, elevated HbA(1c) was a significant predictor only in men (hazard ratio 1.48 [95% CI 1.28-1.71]). In time-dependent models, although a significant effect of HbA(1c) was also seen in women (1.21 [1.00-1.46]), the effect of glycemic control on hypertension development remained stronger in men (1.59 [1.29-1.97], P interaction <0.0001).

Conclusions: Although hyperglycemia is a risk factor for hypertension, its effect is stronger in men compared with women with type 1 diabetes.

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Related in: MedlinePlus

A: Incidence of hypertension by sex and tertiles of HbA1c at study entry. Among men, P value = 0.004 and P value for trend = 0.0008. Among women, P value = 0.47 and P value for trend = 0.31. B: Diabetes duration–adjusted survival curves for hypertension by tertiles of HbA1c at study entry among men. The Pittsburgh EDC study (hazard ratio8.0 to <9.2 2.42 [95% CI 1.43–4.10], P value = 0.0009; hazard ratio >9.2 4.00 [2.35–6.80], P value <0.0001; log-rank P value <0.0001). C: Diabetes duration–adjusted survival curves for hypertension by tertiles of HbA1c at study entry among women. The Pittsburgh EDC study (hazard ratio 8.0–<9.2 1.18 [0.70–1.98], P value = 0.54; HR>9.2 1.58 [0.97–2.58], P value = 0.07; log-rank P value = 0.22).
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Figure 1: A: Incidence of hypertension by sex and tertiles of HbA1c at study entry. Among men, P value = 0.004 and P value for trend = 0.0008. Among women, P value = 0.47 and P value for trend = 0.31. B: Diabetes duration–adjusted survival curves for hypertension by tertiles of HbA1c at study entry among men. The Pittsburgh EDC study (hazard ratio8.0 to <9.2 2.42 [95% CI 1.43–4.10], P value = 0.0009; hazard ratio >9.2 4.00 [2.35–6.80], P value <0.0001; log-rank P value <0.0001). C: Diabetes duration–adjusted survival curves for hypertension by tertiles of HbA1c at study entry among women. The Pittsburgh EDC study (hazard ratio 8.0–<9.2 1.18 [0.70–1.98], P value = 0.54; HR>9.2 1.58 [0.97–2.58], P value = 0.07; log-rank P value = 0.22).

Mentions: To evaluate whether a dissimilar distribution of HbA1c between male and female participants at study entry was responsible for the observed discrepancy in its association with hypertension incidence by sex, we assessed incidence by HbA1c tertiles. As shown in Fig. 1A, the proportion of incident cases was similar by sex within the first HbA1c tertile but appeared to be slightly increased among men compared with women within the second and third tertiles. Moreover, although hypertension incidence appeared to increase linearly with increasing HbA1c tertile among men (P value for trend = 0.0008), a similar increase in risk was not apparent among women (P value for trend = 0.31). Figure 1B and C depicts the diabetes duration–adjusted 18-year survival free of hypertension for men and women, respectively, by tertiles of HbA1c at study entry. These graphs clearly show a strong association between HbA1c and hypertension incidence among men but a much weaker, nonsignificant relationship among women. Thus, compared with men with HbA1c <8%, the estimated relative hazard of developing hypertension was 2.42 (95% CI 1.43–4.10) times higher among those with HbA1c between 8 and 9.2% and four (2.35–6.80) times higher among men whose levels were >9.2%. Among women, however, even levels >9.2% were only associated with a borderline significantly increased hazard compared with HbA1c levels <8% (P = 0.07).


Differential effect of glycemia on the incidence of hypertension by sex: the epidemiology of diabetes complications study.

Costacou T, Orchard TJ - Diabetes Care (2012)

A: Incidence of hypertension by sex and tertiles of HbA1c at study entry. Among men, P value = 0.004 and P value for trend = 0.0008. Among women, P value = 0.47 and P value for trend = 0.31. B: Diabetes duration–adjusted survival curves for hypertension by tertiles of HbA1c at study entry among men. The Pittsburgh EDC study (hazard ratio8.0 to <9.2 2.42 [95% CI 1.43–4.10], P value = 0.0009; hazard ratio >9.2 4.00 [2.35–6.80], P value <0.0001; log-rank P value <0.0001). C: Diabetes duration–adjusted survival curves for hypertension by tertiles of HbA1c at study entry among women. The Pittsburgh EDC study (hazard ratio 8.0–<9.2 1.18 [0.70–1.98], P value = 0.54; HR>9.2 1.58 [0.97–2.58], P value = 0.07; log-rank P value = 0.22).
© Copyright Policy - creative-commons
Related In: Results  -  Collection

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Figure 1: A: Incidence of hypertension by sex and tertiles of HbA1c at study entry. Among men, P value = 0.004 and P value for trend = 0.0008. Among women, P value = 0.47 and P value for trend = 0.31. B: Diabetes duration–adjusted survival curves for hypertension by tertiles of HbA1c at study entry among men. The Pittsburgh EDC study (hazard ratio8.0 to <9.2 2.42 [95% CI 1.43–4.10], P value = 0.0009; hazard ratio >9.2 4.00 [2.35–6.80], P value <0.0001; log-rank P value <0.0001). C: Diabetes duration–adjusted survival curves for hypertension by tertiles of HbA1c at study entry among women. The Pittsburgh EDC study (hazard ratio 8.0–<9.2 1.18 [0.70–1.98], P value = 0.54; HR>9.2 1.58 [0.97–2.58], P value = 0.07; log-rank P value = 0.22).
Mentions: To evaluate whether a dissimilar distribution of HbA1c between male and female participants at study entry was responsible for the observed discrepancy in its association with hypertension incidence by sex, we assessed incidence by HbA1c tertiles. As shown in Fig. 1A, the proportion of incident cases was similar by sex within the first HbA1c tertile but appeared to be slightly increased among men compared with women within the second and third tertiles. Moreover, although hypertension incidence appeared to increase linearly with increasing HbA1c tertile among men (P value for trend = 0.0008), a similar increase in risk was not apparent among women (P value for trend = 0.31). Figure 1B and C depicts the diabetes duration–adjusted 18-year survival free of hypertension for men and women, respectively, by tertiles of HbA1c at study entry. These graphs clearly show a strong association between HbA1c and hypertension incidence among men but a much weaker, nonsignificant relationship among women. Thus, compared with men with HbA1c <8%, the estimated relative hazard of developing hypertension was 2.42 (95% CI 1.43–4.10) times higher among those with HbA1c between 8 and 9.2% and four (2.35–6.80) times higher among men whose levels were >9.2%. Among women, however, even levels >9.2% were only associated with a borderline significantly increased hazard compared with HbA1c levels <8% (P = 0.07).

Bottom Line: A significant interaction was noted between sex and HbA(1c), and separate models were constructed by sex.Multivariably, elevated HbA(1c) was a significant predictor only in men (hazard ratio 1.48 [95% CI 1.28-1.71]).Although hyperglycemia is a risk factor for hypertension, its effect is stronger in men compared with women with type 1 diabetes.

View Article: PubMed Central - PubMed

Affiliation: Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA, USA. costacout@edc.pitt.edu

ABSTRACT

Objective: Diabetes Control and Complications Trial/Epidemiology of Diabetes Intervention and Complications analyses demonstrated that intensive insulin therapy was inversely associated with incident hypertension. We thus sought to confirm these observations and, given sex differences in other type 1 diabetes complications and risk factors, assessed whether any such associations differ by sex.

Research design and methods: Participants of a prospective cohort of childhood-onset type 1 diabetes, free of hypertension at study entry (baseline mean age, 28 years; diabetes duration, 19 years), were selected for study (n = 510). Hypertension incidence was defined as blood pressure >140/90 mmHg or use of hypertension medications in two consecutive visits. Intensive insulin therapy was defined as three or more injections (or pump) and four or more glucose tests daily. Baseline predictors of hypertension were examined using Cox proportional hazards models. Models with time-dependent updated means of baseline significant variables were also constructed.

Results: Hypertension incidence over 18 years of follow-up was marginally higher in men than in women (43.2 vs. 35.4%, P = 0.07). A significant interaction was noted between sex and HbA(1c), and separate models were constructed by sex. Multivariably, elevated HbA(1c) was a significant predictor only in men (hazard ratio 1.48 [95% CI 1.28-1.71]). In time-dependent models, although a significant effect of HbA(1c) was also seen in women (1.21 [1.00-1.46]), the effect of glycemic control on hypertension development remained stronger in men (1.59 [1.29-1.97], P interaction <0.0001).

Conclusions: Although hyperglycemia is a risk factor for hypertension, its effect is stronger in men compared with women with type 1 diabetes.

Show MeSH
Related in: MedlinePlus