Synergistic interaction of hypertension and diabetes on chronic kidney disease: Insights from the National Health and Nutrition Examination Survey 1999-2006

High fat diet is protective against kidney injury in hypertensive-diabetic mice, but leads to liver injury

Chronic kidney disease (CKD) is a worldwide health burden with increases risk of end-stage renal function if left untreated. CKD induced in the context of metabolic syndrome (MS) increases risks of hypertension, hyperglycemia, excess body fat and dyslipidemia. To test if combining a high-fat diet (HFD) regimen onto the hypertensive/ diabetic phenotype would mimic features of MS induced-CKD in mice, hyperglycemia was induced in genetically hypertensive mice (Lin), followed by HFD regimen. For that, 8-week-old male were subjected to streptozotocin (STZ) intraperitoneal (i.p.) injections (50 mg/kg, 5 days consecutive). LinSTZ were fed a 60% kCal HFD for 8 weeks. Lin mice treated with STZ developed polydipsia, became hypertensive and hyperglycemic. HFD induced weight gain, protected against glomerular hypertrophy, scarring, and albuminuria at endpoint compared to regular diet fed LinSTZ. On the other hand, HFD induced steatosis, liver fibrosis, inflammation, and increase in AST/ALT ratio, characteristics of non-alcoholic liver disease. Taken together, our results show that LinSTZ mice fed a HFD did not lead to a more robust model of MS-induced CKD, protected against kidney injury, but inducing liver damage. More studies are necessary to understand the kidney protective mechanisms of HFD when superimposed with hypertension and type 1 diabetes.

Interaction effect of blood glucose and pressure on the risk of chronic kidney disease: a population-based prospective cohort study

OBJECTIVE

To evaluate the interaction effect of blood glucose and blood pressure on the risk of chronic kidney disease (CKD).

METHODS

31,165 subjects were selected without CKD at baseline and had completed the first follow-up from "Jinchang cohort". Cox regression model and restricted cubic splines functions were used to evaluate the effects of blood glucose or pressure on the incidence of CKD and dose-response relationship after adjusting for confounding covariates. Synergic effect was assessed by the multiplicative or additive interaction scale.

RESULTS

Among 31,165 subjects, 1307 new-onset CKD were observed during 68905.78 person-years follow-up, and the incidence density was 18.97 per 1000 person-years. The risk of CKD gradually increased with the increase of blood pressure in diabetes, pre-diabetes and normal groups (P_trend < 0.05). And, the risk was greatest when SBP/DBP reached ≥150/≥110 mmHg in three groups, and HRs (95% CI) were 1.610 (1.070-2.422), 2.142 (1.396-3.288) and 2.455 (1.941-3.106), respectively. Additionally, among hypertension, pre-hypertension and normal groups, the risk of CKD increased by 16.0%, 14.3% and 25.2% for each 1 mmol/L of FPG. When FPG level was more than 9.0 mmol/L, the risk was greatest and adjusted HRs (95% CI) were 2.856 (2.176-3.748), 2.979 (1.828-4.854) and 7.520 (4.517-12.519). Furthermore, the risk was highest when hypertension was accompanied by diabetes (HR = 4.915, 95% CI: 3.923-6.157). This analysis supported a less than multiplicative effect (HR = 0.634, 95% CI: 0.417-0.964) for the interaction term of diabetes and hypertension, while there was no additive interaction towards CKD in all interaction term.

CONCLUSIONS

Blood glucose and pressure were independent risk factors in incidence of CKD, but there was only a negative multiplicative interaction between hypertension and diabetes, but no additive interaction effect between them.

Interaction effect between overweight/obesity and alcohol consumption on hypertension risk in China: a longitudinal study

OBJECTIVE

To explore the interaction effect between overweight/obesity and alcohol consumption on hypertension risk.

DESIGN

A longitudinal study of the independent and combined effects of hypertension risk factors.

SETTING

Twelve provinces in China, including Beijing Liaoning, Heilongjiang, Shanghai, Jiangsu, Shandong, Henan, Hubei, Hunan, Guangxi, Guizhou and Chongqing.

PARTICIPANTS

Longitudinal data of China Health and Nutrition Survey, collected between 2011 and 2015, were used in this study. A total of 13 121 residents from 12 provinces were included and completed physical examinations and questionnaires at baseline.

OUTCOME

First incidence of hypertension.

RESULTS

Over a mean follow-up of 4 years, 690 incident hypertension cases were reported. After adjusting for age, gender, education level, marital status, physical activity, diabetes and smoking, high body mass index (BMI) and light drinking (OR=5.07, 95% CI 3.06 to 8.41), high waist circumference (WC) and light drinking (OR=4.81, 95% CI 2.92 to 7.91), high waist hip ratio and light drinking (OR=2.85, 95% CI 1.84 to 4.42) were the highest risk of all participants in the three combinations. Multiplicative interaction measures were statistically significant in overweight/obesity and drinking/light drinking/heavy drinking categories in men (p<0.05). Additive interactions were observed between high BMI and drinking in men (relative excess risk due to interaction=1.75, 95% CI 0.85 to 2.65, attributable proportion due to interaction=0.56, 95% CI 0.36 to 0.76, synergy index=6.43, 95% CI 1.02 to 28.84).

CONCLUSIONS

Measures of body weight and size, particularly BMI and WC, appear to interact synergistically with alcohol consumption to increase the risk of hypertension in the Chinese population. Given that approximately 245 million people in China have hypertension, and that hypertension is a major cause of cardiovascular disease worldwide, our results may have implications for chronic disease prevention.

Why take organ damage in hypertension seriously?

The focus of recent European guidelines has been early initiation of antihypertensive therapy in risk groups, rapid achievement of target blood pressure with fixed combinations of antihypertensive drugs, and the best possible management of an individuals cardiovascular risk. Early intervention in the development of hypertension-mediated organ damage (HMOD) has been shown to have an effect on the subsequent reduction in the risk of cardiovascular events. The point of HMOD origination correlates with the magnitude and duration of blood pressure elevation, and there is no clearly defined boundary from which vascular damage begins to develop. A reduction in blood pressure with pharmacotherapy demonstrably decreases the risk of ischaemic heart disease, stroke, as well as the mortality rate (1). Large clinical trials have consistently shown a significant reduction in the risk of these complications with antihypertensive medications across the entire spectrum from mild to severe hypertension, including hypertension in the elderly as well as isolated systolic hypertension (2). Based on the latest knowledge, a reduction in blood pressure by a mere 5 mm Hg has a cardioprotective effect even in normotensive individuals, which fundamentally changes the view on the diagnosis and definition of hypertension as a disease (3).

Epidemiological characteristics of hypertension, impaired fasting capillary glucose and their comorbidity: a retrospective cross-sectional population-based study of rural adolescents in Southeast Nigeria

OBJECTIVE

To assess the prevalence of hypertension, impaired fasting capillary glucose (IFCG) and coexistence of both as well as determinants of these conditions among rural adolescents.

DESIGN

A retrospective cross-sectional population-based study.

SETTING

Three rural communities in southeast Nigeria.

PARTICIPANTS

A total of 401 adolescents (10 - 19 years) selected through a five-stage sampling technique completed the study. Sick adolescents, pregnant and nursing adolescent mothers were excluded.

PRIMARY OUTCOME MEASURES

Prevalence and determinants of hypertension, IFCG and comorbidity of both were assessed through weight, height, blood pressure, fasting capillary glucose measurements and statistical analysis.

RESULTS

Prehypertension (10.7%), hypertension alone (12.7%), IFCG alone (11.0%), diabetes (0.2%) and hypertension with IFCG (6.2%) were prevalent among the adolescents. The adolescents aged 15 - 19 years were less likely to be affected by hypertension alone (adjusted OR (AOR)=0.36, 95% CI 0.18 to 0.74, p<0.01). The likelihood of having hypertension alone was three times higher among those who smoked any substance (AOR=3.43, 95% CI 1.34 to 8.78, p<0.05) and 2.85 times higher among those who consumed alcohol (AOR=2.85, 95% CI 1.33 to 6.10, p<0.01). Meal skipping (AOR=2.69, 95% CI 1.16 to 6.25, p<0.05), consumption of fried/baked snacks (AOR=15.46, 95% CI 1.62 to 147.37, p<0.05) and vegetables (AOR=2.27, 95% CI 1.11 to 4.66, p<0.05) were also significant risk factors of hypertension alone. Skipping meals (AOR=2.15, 95% CI 0. 93 to 4.99, p>0.05) and longer than 7 hours of night sleep (AOR=1.88, 95% CI 0.94 TO 3.73, p>0.05) increased the risk of IFCG alone by twofold. Female adolescents (AOR=0.29, 95% CI 0.10 to 0.78, p<0.05) and those who consumed fried/baked snacks (AOR=0.09, 95% CI 0.02 to 0.37, p<0.01) were less likely to have hypertension with IFPG than males and those who consumed non-fried/baked snacks, respectively.

CONCLUSION

This study reported relatively low prevalence of hypertension alone, IFCG alone, hypertension with IFCG and epidemiological characteristics that can become focus of interventions to curtail the emergence of cardiovascular events at an early age. Awareness creation through health and nutrition education is emphasised.